The M16, or in the early days of the Vietnam War, the XM16E1, had very mixed reviews with the troops. In the early part of the war around 1965 the Black Rifle first went to war with the 7th Cavalry in the battle of the Ia Drang Valley. The rifles were in-country prior to this battle with advisors but this is the first time the rifle would be used by a US military unit in direct combat with North
Vietnamese regular troops.

Joe Galloway was born in Refugio, Texas and is a journalist by profession. He is best known as a United Press International (UPI) combat correspondent who covered the early days of the Vietnam War. He covered the Battle of the Ia Drang Valley where he and now-retired General Hal Moore would eventually write a book titled “We Were Soldiers Once, and Young”. That book would be made into one of the finest war films of all time, “We Were Soldiers.” On 14 November, 1965 approximately 450 soldiers from the 7th Cavalry Air Mobile Division landed in Landing Zone X-ray located west of Plei Me in the Central Highlands of South Vietnam (precisely at the foot step of the Chu Pong massif). They unknowingly landed under a base camp of an entire North Vietnamese Army Regiment (nearly 4000 men). Joe Galloway flew in on a helicopter the 1st night of the attack. Joe Galloway is in a position to give SAR readers his first impression of the rifle, tell from his first hand experience how the rifle performed during the battle as well as the soldier’s perception of the rifle- being this was the first battle not only between US and NVA regular Army forces but also the US forces’ first major battle using the new rifles.

SAR: When did you arrive in South Vietnam?

Galloway: I arrived in South Vietnam early in April 1965 after the 1st Battalion of 9th Marines landed at Da Nang, and was immediately sent to Da Nang to cover the Marines. (Editor’s Note: 1st Battalion, 9th Marines are the fabled “Walking Dead).

SAR: Do you recall what weapons the Marines were carrying at that time? When did you first see the M16/XM16E1?

Galloway: They all carried M14 rifles and continued to do so for much of 1965 and into early 1966. My first close look at the new M16 rifles came in encounters with/coverage of Special Forces troops and 173rd Airborne troops in the Summer of 1965. I don’t recall any specific complaints about the weapon from those units at the time. My first thoughts were that it was light, easy to carry and easier to carry a whole lot more loaded magazines than the M14.

SAR: What was your first close encounter with the new rifle?

Galloway: My close acquaintance with the M16 came in October 1965 when I wangled a chopper ride into Plei Me Special Forces Camp in the Highlands as it was under siege by a Regiment of NV Regulars. Maj. Charlie Beckwith (Creator of Delta Force) was temporary camp commander. He ordered me to man a .30 cal. Air-cooled machine gun, saying he had “No vacancy for a goddam reporter.” After the siege was lifted and I was about to join a 1st Cavalry battalion sweeping the hills around the camp I went to say my goodbyes to Maj. Beckwith. He said: “You ain’t carrying a piece, Son.” I said: “Technically speaking, in spite of the use you made of me these last days and nights, I am a civilian non-combatant.” He said: “Ain’t no such thing in these mountains. Sergeant, go get this guy a rifle and a sack of magazines.” The sergeant came back with an M16 and 20 loaded magazines. I slung the rifle and marched off with the Cav.

SAR: Do you recall any conversations with then Lt Col Hal Moore and SGM Basil Plumley about their thoughts of this new weapon they were taking into battle?

Galloway: LTC Hal Moore liked and carried an M16 and I never heard him say anything but good things about it. SGM Basil Plumley thought it was a “plastic toy” and wouldn’t carry one. He wore a Colt 1911 .45 pistol throughout his first year in RVN.

In 2007 while working on a project for Picatinny Arsenal this author had an opportunity to interview Retired General Hal Moore regarding his thoughts of the new rifle. He had stated that he was fond of the rifle. He felt that most of the weapons that malfunctioned during the battle were from excessive operation. They were in constant battle for three days and two nights with little let up. He said he was not a weapons expert but he believed that the new rifle was superior to the M14 particularly in the close quarter fighting of the battle in the Ia Drang Valley.

SAR: Upon your arrival to the battlefield, did you notice- either see or hear of anyone complaining of malfunctioning weapons, or worse did you see anyone laying dead next to a jammed rifle?

Galloway: On arrival in LZ XRAY in the Ia Drang on 14 November, 1965 I saw a lot of Americans dead from the afternoon of bitter combat. I heard no one say that any of them had died due to failure of their rifles, then or later. LTC Moore credited his brave soldiers “and this rifle” in comments to reporters after the fight ended. Later I would hear from LT Rick Rescorla (B Co. 2nd Btn 7th Cav) say that his troops suffered a number of jammed M16s—so many that he assigned three men to each foxhole; two shooting and one with a steel rod clearing jams and reloading for the shooters. His was the only complaint about that rifle that I heard about.

At the time of this battle the XM16E1 rifles were fairly new. They did not have chrome plated barrels. The ammunition they had would have been the original IMR propellant the rifle was designed around. Ball propellant and the problems it caused would be after this battle. General Moore also stated that there was an issue with the supply of the ammunition for the rifles. He said they should have dropped in loaded magazines instead of ammo that had to be removed from a box and loaded into magazines. They had few lulls in combat for weapons maintenance as well as reloading magazines.

SAR: I am sure this is really difficult to remember but can you recall seeing riflemen holding the trigger down and spraying ammunition and then running out of ammo in battle? This question comes from the 1980’s M16A2 program where the Marines wanted to remove the AUTO position in favor of a 3-round Burst mode. They claimed it would help conserve ammunition so a Marine would not shoot up all his ammo at once and be left with empty magazines unable to fight. Also similar to World War II with the adoption of the M1 Garand with the 8 shot stripper clip instead of a box magazine. Detractors from this theory felt ammunition expenditure was a matter of troop firing discipline.

Galloway: I do not recall any of what I would call wild automatic firing. Those troops were disciplined and acutely aware that if they ran out of ammo they would end up dead. The chopper that brought me in at dark on first day of the battle contained ammo and grenade resupply in cases, as well as 5 gal plastic water jugs. The choppers would keep us well supplied with ammo as the battle went on. When it was all over the choppers had to haul out excess supplies of ammo that had gone unused. Ammo resupply was in cases of boxed loose rounds, not preloaded magazines. The troops had to reload their magazines during the lulls.

SAR: Do you recall anyone complaining about the stopping power of the 5.56mm round during the battle. As you may or may not know the rifle was given the nickname “poodle shooter” due to its .224 diameter projectile.

Galloway: No one complained in my hearing that the M16 had less stopping power vs. AK47. The troops were killing the enemy all around us.

SAR: During your time in-country or at any time covering the war, do you recall hearing of the rifles having serious malfunction issues and If so what do you recall they were?

Galloway: Referring to late 1966 early 1967 and complaints of M16s jamming? I heard this from the Marines primarily; that they hated the M16 and wanted their M14s back. I also heard that the primary problem was the M16s were handed out with little or no instruction on cleaning the weapon. Therefore the Marines cleaned and oiled the M16 exactly as they had done with the M14: Lots of oil, which in turn led to lots of jammed rifles. Once they learned to use dry graphite lube in place of gun oil the rifles worked better. And once the rifle was redesigned around 1968 the complaints faded away.

SAR: You had said that you had carried a M16 and that you had used it during the battle of Ia Drang. What were your personal experience with the rifle you carried?

Galloway: I carried the M16 that Maj. Beckwith gave me throughout the rest of my first tour in Vietnam. I made very sparing use of it because that was not my primary job. I did use it in the Ia Drang when things got very hairy the 2nd day of battle. Mine worked fine. Near the end of my tour I traded the M16 to a Marine PAO lieutenant who later complained that it jammed on him during a firefight. Possibly a cleaning or oiling problem.

Author’s Notes and opinion in closing: Over the past 50 years the M16 has been loved by some and hated by others. In those early days, the Army felt the end would justify the means and the Army would just stay with their home-grown M14. Even though their “means” was basically sabotaging the rifle and putting a rifle that did not work properly into the hands of American soldiers in a foreign land, and they knew it. You do not conduct engineering trials in the field, period. Army tradition and keeping the government arsenals pumping out M14 rifles and protecting all those jobs and high ranking officers clouded the judgment of what was in the best interest for the American soldier; which is what should have been their top priority and a solemn duty. The rifle as presented by ArmaLite was an excellent weapon but it was not fully developed. It is the job of the Ordnance Corps to get it in order to issue to the troops. After the Congressional hearing in 1968 and the Army being determined to be “borderline criminally negligent” the Army corrected the issues and those serving after 1968 had little trouble. The M16A1 proved to be the ideal rifle for the War in Vietnam. It has gone on to evolve to the M16A2 and now to the M16A4 serving n both Iraq and Afghanistan. The Vietnam era XM177-series of carbines has evolved to the M4 carbine which has become general issue throughout the US military. Controversy still follows the rifle today. The M16/M4 series has been attempted to be replaced with the Advanced Combat Rifle Program as well as the more recent Individual Carbine competition. According to the Army there is nothing after more than 50 years that offers a “significant leap in technology” over Gene Stoners design. The Army has just ordered a significant number of M4A1 carbines from FN and Colt. The M16A4 demand is dwindling as the M4A1 is the weapon of choice.

SAR would like to thank Joe Galloway for this interview. In this author’s opinion Joe is one of the finest combat correspondents ever. His character and credibility are top rate. His life has been dedicated to honoring the Vietnam soldiers and keeping the memory alive of the men who fought and died in that valley of death. Joes work along with Hal More have forever immortalized the men of the 7th cavalry into the hearts of the American public with the book and movie “We Were Soldiers.” Joe’s point of view is very credible and reliable on the early days of the M16. Joe has no dog in the fight. He is not an arms expert nor an army ordnance officer. He was there with the men and saw from unbiased eyes what happened from the soldier’s perspective. For the soldiers who experienced fatal stoppages and the ones who witnessed them, they will not care what mechanically went wrong and why. All they know is the rifle failed and it cost lives. The story does not end there. There were causes both political and economic that went into those fateful decisions. Once investigated and the Congressional hearing calling out and getting the Army to fix the rifle, the family of weapons has served with distinction for more than 50 years and is in no danger of being replaced any time soon.

Over the last 15 or so years, the sniper rifle in both concept and rifle has changed.It was not until the Vietnam War where a semiautomatic sniper rifle based on the M14 rifle was introduced. However, it did not perform as well as the bolt action counterpart and required a full time gunsmith to keep it working. So the semiautomatic rifle was in limited use with the standard still being the bolt action sniper rifle.

However, in the late 1950s a rifle was designed by Eugene M. Stoner at ArmaLite, Inc. called the AR-10. ArmaLite was a division of Fairchild Engine and Aircraft located in Hollywood, California. This revolutionary rifle was truly “Tomorrow’s Rifle Today,” that was more true than anyone knew back then. Although it never had a chance to compete head-on with the M14 for the next U.S. infantry rifle due to Army politics, as well as the deep rooted thought of a rifle having to be made from steel and wood, the AR-10 did get noticed. During its limited testing it was known to be the most accurate auto loading rifle made as said by the testers from Ordnance Corps. Limited numbers of AR-10 rifles were manufactured in the Netherlands by Artillerie-Inrichtingen. They were manufactured for Dutch Army trials as well as sold in limited numbers to some other countries including, Sudan, Cuba, Italy, Guatemala and Portugal. As predicted, the M14 was adopted and the AR-10 was tossed in the Ordnance Corps scrap heap. The requirement came down to scale the AR-10 down to a .22 caliber and the AR-15 was born. The rights were sold for the AR-15 as well as the AR-10 to Colt’s Patent Firearms Manufacturing Company. Colt went on to produce the AR-15 but ignored the AR-10 design. That was left for other companies to capitalize on. To trace the AR-10 lineage to today’s most advanced sniper rifle we must skip ahead nearly 30 or so years ahead to 1991.

In November of 1991, a Mission Needs Statement was drafted for an Enhanced Sniper Support Team Weapon (SSTW). This was written by Lt. Col. David Lutz while serving as the Program Manager for Infantry Weapons at MARCORSYSCOM at Quantico, VA. This documentation was an effort to restart a cancelled Designated Marksman Weapon program (DMR) based on the M14 which could not be made to do all the things needed in a logistically supportable package acceptable to the Fleet Marine Forces. Its requirement document was weak because it totally lacked objectivity in doing a mission analysis or seeking other viable solutions. At the time, the current SSTW was the M16A2 rifle. This weapon supported the M40A1 sniper rifle in the two man scout sniper team. The M16A2 SSTW was used to engage close-up targets and provide rapid fire suppressive fire if needed. Some noted deficiencies were the M16A2’s poor interface with the soldier when having optics mounted, including night vision. The current issue M855 ball ammunition did not meet the accuracy specifications of a SSTW.

The enhanced SSTW would fill the role of a 0 to 600 meter intermediate range sniper rifle. It would have ammunition interchangeability with the M40A1 7.62x51mm sniper rifle and it would have the ability to mount a sound suppressor. Optics would be mounted in-line with the shooter’s eyes for a comfortable mount. This rifle will also have to overcome current problems with the unit, direct, general, and depot support problems (availability and maintainability) long associated with the hand-built and Marine Corps customized M40A1.

Lt. Col. Lutz recalls that he knew of (5 each) Dutch NATO AR-10s that were in a bunker at Picatinny Arsenal from when he was stationed there during 1980-83. So he had one of his successors, USMC Liaison Officer Maj. Dody Knootz, pick out one that shot the best and “temporary loan” it to them at Quantico. Several modifications were made with the most significant being the carrying handle cut off and a weaver rail attached to the upper receiver. The AR-10 had some of the improved M16A2 components added to it including the pistol grip and handguards. All this was to make it look like and use A2 service rifle parts and training. Additionally, they removed the AR-10’s faux muzzle, which incorporated a grenade launching spigot, exposed its skinny barrel and threaded muzzle. Lutz recalls sending the upper to Phil Seberger to have a suppressor made & fitted to it.

As recalled by Lutz, as a concept demonstrator it was a success. “When my general came out to fire it he brought with him his Australian Army Liaison Officer, a full colonel. My general was reluctant to fire the weapon as I presented it to him, and handed if off to the Australian Colonel. Offhand, the Colonel hit a steel gong at 100 yards with 20 of 20 shots (suppressed). When he handed the rifle back to my general, he said “General, this is the finest rifle I have ever fired.” When the General handed the rifle back to me, he said “Dave, you have a program.” I guess the rest is history…” Though the concept was sound, the Marines or big army were not ready for a semiautomatic sniper rifle, at least not yet. So the AR-10 lay dormant once again until the early 1990s. Even though the original DMR program failed, the STSW maintained life in the requirement and allowed Rifle Team Equipment builders at Quantico to produce more prototype M14 based variants as “interim measures.” This eventually took on a “life of its own,” and an M14 based program eventually found traction as the M39 Enhanced Marksman Rifle (EMR). However, the M39 is one of the weapons being replaced by the Marines recent purchase of M110s. The M110 was inherently able to meet the STSW requirement for mounting of Night Vision without lose of zero, sound suppressor integration, M16 ordnance maintenance and training commonality, supply system commonality and cross-service weapon commonality.

The name Eugene Stoner, although not as well known as Browning, is just as significant in the history of the gun. Stoner’s design is the longest service rifle in U.S. military history. During Stoner’s ArmaLite days his goal was to develop 7.62x51mm weapons. He was very fond of his direct gas system. After the M14 was selected, the future was only in the smaller caliber round so Stoner went on to develop other rifles to fire the 5.56mm cartridge including the AR-18 and the Stoner weapon series. He never quite forgot his AR-10. In the early 1990s, Stoner went to work with C. Reed Knight, Jr., the president of Knight’s Armament Company. The union spawned the rebirth of the AR-10. This would be the SR-25 (Stoner Rifle-25 (15+10)). This rifle would be an AR-10 but would take on the advancements of the M16A2 rifle and maintain 60% parts compatibility.

Released in the early 1990s, the SR-25 Match Rifle was equipped with a 24-inch Remington 5R match grade barrel – the same barrel blanks used on the M24 sniper rifle. The heavy barrel was free floating with a fiberglass handguard. The rifle was equipped with a flat top upper receiver with the Mil-Std 1913 rail and the receivers were made from aluminum extrusions. The rifle was equipped with a 2-stage match grade trigger. The bolt carrier group kept with the original AR-10 in that it was chrome plated and it also sported the captive firing pin retainer pin. These were not mass produced rifles. The uppers and lowers were mated together and had matching serial numbers to identify them. They were specifically designed around the 168gr OTM Match cartridge. Using this factory load, the ogive of the bullet set right on the rifling. This is something match shooters want to accomplish due to not wanting the bullet to “jump” into the rifling thus maintaining control of the projectile right from the moment of chambering. The original rifles used the standard “waffle” pattern 20-round magazine and later a steel magazine that looked more like an M16 20-round magazine in appearance. The SR-25 was sold initially through commercial channels that funded R&D. Every SR-25 was test fired at the factory and provided with a target. Knight guaranteed that this rifle would fire 1 MOA or under with factory ammunition. Gene Stoner would work with Knight up until his death in 1997.

The SR-25 quickly gained its reputation for precision accuracy and reliability and its versatility and benefits were appreciated right away by the special operation forces. SOCOM liked the idea of having a semiautomatic rifle that held 20 rounds of ammunition and rivaled the M24 and M40A1 bolt action rifles. They also liked that you could engage multiple targets in less than half the time they could with a manual bolt action rifle.

After more than 40 years, the AR-10 would have its day. In May of 2000, the U.S. Navy and SOCOM adopted the SR-25 as their new Mk 11 Mod 0. This would be follow by another contract in 2007 for 9.9 million dollars with the need from the Global War On Terrorism. The Mk11 had some departures from the original design. Designed to meet the SOCCOM requirement, the rifle was designed to fire the M118 and M118LR match grade 7.62x51mm NATO ammunition. The Remington barrel was replaced with an Obermeyer barrel and was shortened to 20 inches and equipped with a mount for a quick detachable sound suppressor also developed by Knight’s Armament Company. The 11.35-inch Rail Accessory System free floating handguard provided quad Mil-Std 1913 rails enabling attachment of any given number of accessories including night vision, lasers, tactical lights and bipods. The standard M16A2 stock and pistol grip are used for parts commonality. A flip up front sight was added to the gas block as well as KAC’s fully adjustable back-up iron sight was added. The rifle was equipped with 20-round magazines, a Leupold Vari-X mil dot scope with detachable rings and a Harris bipod. The Mk11 weighs 15.3 pounds unloaded and has an overall length of 45.4 inches. The Mk11 would see action with U.S. Special Operations troops all over the world. The weight of the complete Mk11 Mod 0 with the Leupold 3.5×10 scope & SIMRAD adapter, bipod adapter with LM type S Bipod is 13.7 pounds.

Enter the M110 SASS (Semi Automatic Sniper System)

The success of the Mk11 was undeniable and spread to the other branches of the military – the sniper units in particular. Seeing the benefits in September of 2005, Knight’s won the contract for the M110 SASS rifle. The M110 was to replace the M24 bolt action sniper rifles in the U.S. Army. The M110 trials had many submissions including ArmaLite, Remington and DPMS Panther Arms. It would not be until April of 2008 that the M110 would see its first combat action with U.S. Army snipers from Task Force Fury in Afghanistan. During the early M110 period, the Marines purchased 180 XM110 variants they designated Mk11 Mod 1 and then in 2010 ordered 803 M110 rifles.

The M110 has many similarities to the Mk11 Mod 0, however with many enhancements. . The stock on the M110 is adjustable for length with a dial on the rear allowing for the length to be increased or decreased as desired. The stock has one moveable sling swivel mount on the bottom rear plus two QD mounts on the front of the stock on each side. The receiver is manufactured from an aluminum forging and incorporates fully ambidextrous selector lever, bolt catch and magazine release. A button right above the magazine catch on the right side of the receiver is the ambi-bolt release. This allows the right handed shooter to release the bolt without his hand ever leaving the pistol grip. On the left side of the receiver under the bolt catch is a button to release the magazine for a left handed shooter. The trigger is Knight’s 2-stage match trigger, which is exceptional for a sniper rifle.

The upper receiver utilizes the new URX (Upper Receiver Extending) free floating rail with an integral folding front sight. This saves space and makes for a dependable back-up sight. The bottom of the handguard is removable for cleaning. Quad Mil-Std 1913 rails allow attachment of any accessory imaginable. The top rail is continuous for adding thermal, night vision and scopes. The handguard comes with three KAC rail protectors that allow the rifle to be shot in a normal shooting position. It is also equipped with a Harris Type S bipod. The 20 inch Obermeyer heavy barrel has 5R grooves with a 1 turn in 11 inch twist that optimizes the 168 and 175gr match bullets of the M118 and M118LR ammunition. The M110 barrel has an A2-style compensator attached to the end. The pinned-on gas block has a Mil-Std 1913 rail on top of it. The M110 is a self-regulated direct gas operated rifle. The upper receiver is manufactured from a forging and now has an integrated fired cartridge case deflector. Early rifles, due to the upper being made from an extrusion, had the fired cartridge case deflector attached to the rail as a separate piece.

The bolt carrier group follows in the tradition of the original AR-10 in that it is chrome plated making for ease of cleaning. The bolt carrier has a captive firing pin retainer pin that prevents it from being lost during cleaning. The bolt utilizes a 1-piece gas ring that is much more durable than the standard 3-ring set. The extractor and, in particular the spring, have been enhanced since the inception of the rifle.

The M110 is packed with four 20-round and four 10-round magazines and pouches. The M110 can also use the Magpul LMag as well.

The optic used is the Leupold 3.5×10 Illuminated Reticle SASS scope with .5 MOA elevation clicks and 30mm SASS mount manufactured by Knight’s. The shooter can adjust the brightness of the reticle to suit the lighting conditions he faces. The scope is provided with lens covers.

The SASS also is equipped with a Knight’s Armament Company sound suppressor. The suppressor interfaces with two vertical slots cut on both sides of the gas block. There is an alignment pin on the underside of the gas block that prevents improper installation. The suppressor has a decibel reduction of -28dB.

Additional accessories include an operator’s repair parts kit that includes scope ring cap screws, bolt rings, extractor assembly, spring, pin and buffer, cam pin and firing pin. Am optics cleaning kit is provided and a torque wrench for the scope mounts. A complete cleaning system is provided as well. This includes an Otis DMR/M14 7.62 cleaning kit, Dewey rod and bore guide, multiple brushes, rod ends, pipe cleaners and swabs. Cleaning patches a bore snake and CLP is provided as well. A sling is provided as well. All this is provided in a large Hardigg box that is hermetically sealed with a pressure release valve.

The ammunition used in this test and evaluation firing was the M110 Silver State Armory (SSA) M118LR ammunition. There were 200 rounds fired with the barrel being cleaned every 10 rounds. The range was 100 meters and the rifle shot consistently sub-MOA. The best group was 5 rounds in a 1/2 inch group. The average was 3/4 inches. This is accuracy of a match bolt action rifle. Silver State Armory ammunition is match grade and they manufacture their own brass cartridge cases and blend their own powders to the particular load. Additional rounds of the 168gr OTM ammunition were fired with the same results as the M118LR.

It this shooter’s opinion there is no bolt action rifle out there that can beat the M110 on accuracy, speed and firepower. A sniper with a M110 can easily engage the same number of targets in less than half the time a well trained sniper can with a bolt action rifle. The suppressor makes it that much better: less noise, less invitation to reveal your position and no affect on accuracy. As expected, no malfunctions of any sort were encountered with the M110.

The M110 has a weight of 12.82 pounds equipped with iron sights, bipod adapter and scope. With M118LR ammunition the muzzle velocity is 2,571 feet per second. The overall length of the M110 is 40.5 inches with the stock at its shortest setting. The sound suppressor only adds 1.62 pounds to the rifle. The maximum effective range is 875 yards and is subjective to the skill of the shooter.

It is most unfortunate Gene Stoner did not live to see his AR-10 finally get into the U.S. inventory and equip the most elite snipers this world has ever known. He was way ahead of everyone in the late 1950s; they just did not have the vision to see it. Gene Stoner’s legacy has been the defense of this country and allies for nearly 50 years and being one of the most brilliant weapons designers of all time. Thanks to Reed Knight, Stoners vision was realized, produced and reintroduced to the U.S. military. Combining the genius of Gene Stoner with Knight’s technical and manufacturing abilities of KAC, the AR-10 will be with us for another 50 years.

When one hears the name Knight’s Armament Company (KAC) and/or their president’s name, C. Reed Knight, Jr., one automatically thinks of world class quality and ingenuity. The out of the box thinking has made KAC a defense contractor to be reckoned with; one that is known to supply our most elite special operations forces. The downside is that if you are not military, you waited a long time to get any of KAC’s high end weapons. When the company started out with its development of the renowned SR-25, development was funded through commercial sales. KAC has never mass produced any small arm as attention to detail and strict quality control prohibit this. Every SR-25 that leaves the factory is provided with a test target showing it fired less than 1 MOA prior to it leaving the factory. When news of a new 5.56mm rifle that KAC was introducing was released, it was anticipated that this weapon was going to be in a class all its own. Reed Knight was not just going to come out with a standard black rifle with his name on it – the rifle would be in a class by itself: and we were not disappointed.

As of this writing, the market is awash with black rifles. Nearly every major manufacturer has their own derivative of the black rifle with most M4-type clones with standard features. Relatively few of these weapons are combat grade weapons. Most are made specifically to cater to the commercial market where price is a concern amongst others. However, for those who stand ready to make combat reliable weapons, severe attention to detail, stringent quality control and relentless pursuit of ways to improve the weapon systems are constantly sought. Few manufacturers truly step up to the plate to build combat reliable weapon systems. The cost and facility needed to accomplish such a task are cost prohibitive for many manufacturers.

The SR-15 E3 is very unique in the world of black rifles from muzzle to stock. When designed, the concept was taking the best and making it better. Prior to release, KAC looked at existing weapon systems and looked at the critiques and took them into consideration. They examined the accessories operators were buying to make their weapons more effective and built many of them into their new rifle. With KAC’s involvement with Special Operations soldiers they understood the needs of the operators.

Starting with the barrel, the 16 inch barrel is chrome plated and hammer forged. Many within the SOCOM community feel that hammer forged barrels have longer service life than conventional button cut rifled barrels. They have the Mil-Spec 1/7 inch twist so the barrel will handle any projectile up to 80 grains that could be fed to it. The barrel is free floating in the KAC URX (Upper Receiver Extending) handguard. The URX has quad Mil-Std 1913 rails with a removable lower handguard. The lower handguard is retained by a plunger that is located at the bottom rear of the rail and can be depressed with a bullet tip or suitable tool. The lower handguard is secured (tightened) by two screws, one on each side of the rail. The two screws must be removed before depressing the plunger to remove to lower handguard. There are five integrated sling swivel mounds located on the URX. Two on the front side rails, two on the back side rails and one on the front of the bottom handguard. There are also numerous points that a KAC Sling Swivel Stud Assembly can be installed. Additionally integrated into the URX is a folding front sight. This Integrated Micro-Adjustable Folding Front Sight can be adjusted by hand by a dial. Neither bullet tip nor front sight adjustment tool is needed. The front sight is actuated by pushing inward on a button on the left side of the sight. The front sight post is very unique as well being extremely narrow and round. This is extremely beneficial and will increase accuracy by having a more precise aiming point. The sight is protected by “rabbit ears” to prevent damage. When folded, it has stop notches so optics or accessories can be attached over it.

The SR-15 E3 is provided with a 600 meter adjustable folding rear sight. This is one of the few Back-Up Iron Sights (BUIS) that are adjustable for windage as well as elevation. Of course, any BUIS can be used. Also provided with the rifle for examination was the new line of Micro Sight assemblies. The first is the 600 meter fully adjustable micro sight assembly (KAC part number 25650). This is a smaller and more compact version of the standard one (KAC part number 98474). The other is the 300 meter micro sight assembly (KAC part number 25475). This is a smaller and more compact version of the standard adjustable for windage only (KAC part number 97082). The micro sight assemblies were introduced at the 2009 SHOT Show.

The gas system has been altered from the conventional M4 carbine by utilizing a mid-length gas system. The gas port is placed in between the carbine and rifle gas tube lengths. This gives more dwell time (bolt remains closed longer allowing residual pressure to drop, which allows the cartridge case to contract more before extraction) thus increasing extraction reliability and durability. The URX used on the SR-15 E3 is specifically designed to accommodate the mid-length gas system.

The bolt carrier is a standard M16/M4 carrier with a well staked carrier key. Knights usually fully chrome plates the entire bolt and bolt carrier as their trademark. The SR-15 bolt carrier only had standard chrome plating on the inside of the bolt carrier and carrier key. The outside of the bolt carrier for the SR-15 is the standard Mil-Spec manganese phosphate finish.

The bolt on the other hand is all new. Knight’s were of the mindset to build an improved carbine and to do so would require actual improvements to correct deficiencies. This means the priority is on reliability and durability, not interchangeability. The multi-lug improved E3 bolt is just that. USSOCOM had complained of bolt breakage as the bolts would wear out and more than often they would break at the cam pin slot. Knight’s realized that the only way to increase that strength was to have more material in that area; so that is exactly what they did, by decreasing the diameter of the cam pin allowing more material on the bolt. There is a reduction in the diameter of the firing pin that was the result of creating a solid material recess for the dual extractor springs that astride the firing pin hole. What this adds up to is significant increase in service life of the bolt. Another issue addressed by SOCOM was failures to extract. This was mainly due to worn out extractor springs or lack of use of the newer generation gold springs. The solution was to add a rubber O-ring around the extractor spring assembly. Knight’s took an entire new approach. Rather than band-aid the problem, they created a completely new ejector. The extractor has a “lobster tail” configuration and utilizes two extractor springs instead of one – similar to Karl Lewis’ enhanced bolt. These differ by another major design change by Knights. They moved the location of the extractor pivot pin from the rear quarter to the center. Combine the two extractor springs with the leverage of having the pivot point in the middle you have a major increase in extractor force. A dirt groove was added right behind the extractor claw as well to give dirt a place to go rater than on the extractor claw. Additionally, the locking lug geometry has been changed. The corner edges from the lugs have been rounded off to increase the cross sectional area of the lugs, which increases the strength of the lugs. The bolt lugs are a common failure area of the conventional square lug bolt lugs.

The lower receiver has all been reworked as well. There are and have never been any “stock” weapons to come out of Reed’s factory. Starting at the rear, the LMT SOPMOD stock is used along with a 6-position receiver extension. The stock has a triangular cheek weld along with two removable battery compartments that are water resistant. Also, there are two Integrated Sling Swivel Mounts for the right and left side and a removable rubber buttpad. The lower receiver also has two Integrated Sling Swivel Mounds on the receiver right behind the rear takedown pin. This is a KAC innovation and has not been done in a lower receiver before. These points are preferred by those who like the one-point slings. Moving forward is the KAC ambidextrous selector lever that is not just for south paws as depending on your tactical position you may be holding the rifle in your left hand. Another major innovation by Knight’s is the ambidextrous bolt and magazine catch. The bolt catch is integrated into the lower receiver and is located just above and behind the magazine release button on the right side of the receiver. This enables a right handed shooter to be able to actuate and close the bolt with his trigger finger. Both the magazine and bolt release can be actuated by the trigger finger. The ambidextrous magazine release button is integrated into the lower receiver and is located on the left side right in front of the trigger guard. The ambidextrous magazine release button is easily actuated by the left handed shooters trigger finger. The trigger guard has been redesigned to accommodate a gloved trigger finger and is of Knight’s own design. Like the standard trigger guard, it can be hinged down by depressing the detent. The trigger itself is not stock either and is KAC’s proprietary two-stage trigger. The trigger breaks at 4-1/2 pounds and may be adjusted for as little or more creep and desired.

The sample rifle came with three KAC rail protectors, a vertical pistol grip and one Mil-Spec Okay Industry magazine was provided. That magazine was not stock either and was equipped with a new KAC magazine follower. The follower is identified by its white color and KAC written on the end. This is an anti-tilt follower, which is another reliability enhancement.

The fit and finish of the rifle was superb as what one comes to expect from Reed Knight. It weighed in at a light 6.75 pounds unloaded and measured at 33 inches in length with the stock closed and 36.25 inches with the stock fully extended. The lightweight was extremely surprising considering the enhancements from the basic design. The whole package came in a large black polymer case.

In testing the rifle a few things were added. There was only one thing left this author could think of to enhance the reliability of this rifle even more than KAC already has: that was to feed it with Magpul PMags. Based on this author’s experience, it is the finest magazine made for the black rifle. The PMags with the MagLevel (window) were used. The chosen optic was the Aimpoint CompM4 and 3X magnifier.

The ammunition used in test firing the SR-15 E3 was provided by Silver State Armory (SSA). SSA recently moved into a larger state-of-the-art manufacturing facility in Packwood, Washington. SSA is known for producing high quality match grade tactical and target ammunition and is also one of the few American companies that produce various armor piercing ammunition for law enforcement/military use. The particular ammunition used for this test was 300 rounds of their 5.56mm M193 Ball. This ammunition is actually 5.56mm and loaded in cartridge cases manufactured by Silver State Armory. Accuracy testing was done with Silver State Armory 5.56mm 77gr Sierra OTM (SSAA10075-77Sierra).

When one takes a Knight’s Armament Company weapon to the range, the bar is raised. High expectations are present and when firing the SR-15, there was no disappointment. The rifle was tested on a brisk winter upstate New York afternoon with a chilling 12º F. There were no malfunctions of any kind during testing. In all, more than 500 rounds were fired. The SR-15 shot continuous 1 MOA groups at 100 yards with both Silver State Armory 77 grain OTM and 55 grain FMJ ammunition. The Aimpoint CompM4 with the 3x magnifier worked out extremely well for this distance. Dialing the intensity of the dot down so it did not overpower the size of the bull’s-eye made all the difference. The rifle may serve well as a fighting carbine or a short range containment rifle. It has the reliability and the accuracy to accomplish both tasks.

Knight’s has put out a world class black rifle, one which sets a new standard as to where the black rifle can go and how much more can be done with this timeless design. After more than 40 years this family of weapons continues to evolve. With the talk of a new service weapon it really leads one to ask, “Why?” Properly made black rifles are light, accurate, reliable, user friendly, modular, adaptable and most of all, proven. Knight’s not to long ago was awarded the contract for the U.S. Army M110 sniper rifle system. This moved sniper rifles to another level in the U.S. armed forces. Traditional thinking of having to have a bolt action rifle for it to be accurate had been challenged. The M110 gives every bit of accuracy of the bolt action rifle with the semi-auto firepower allowing up to 50% decrease in engagement time over the current bolt action rifle. KAC is on the cutting edge of black rifle technology and will for sure be a company to follow to see the future of the black rifle.

At SHOT Show 2004, a new black rifle was introduced that was not just a copy of the standard design that most of the industry produce. This black rifle would move the family of weapons into new uncharted territory. Karl Lewis, president of Lewis Machine & Tool (LMT) introduced the MRP, the monolithic rail platform.

The MRP is the first monolithic upper receiver. The upper receiver is machined from a single 7075 T6 aircraft aluminum forging. There are four solid Mil-Std 1913 rails and permit complete zero retention for optics or any other accessory placed on the rails. The upper receiver is equipped with a forward assist, fired cartridge case deflector as well as an ejection port dust cover. All rails are numbered for easy replacement of optics to insure they are placed back in the same position from which they were removed. Removable sling swivel mounts are placed on the end of the MRP at the 3, 6 and 12 o’clock positions. Additionally, mounting points are located on the right and left side at the rear of the handguard area by the ejection port. This permits any type of sling or desired location for the operator’s discretion.

The innovation does not stop with the development of the first one piece monolithic rail platform. The barrel, held in by two bolts, is removable by the user. When the bolts are removed the barrel/gas tube assembly is pulled straight out of the receiver. This enables the 5.56mm caliber weapon to be configured for whatever mission it will be used. If a close quarter combat environment is the mission, a 10.5 inch barrel may be used. If the mission is urban or normal combat ranges, a 14.5 or 16 inch barrel may be used. If longer range is required, an 18 or 20 inch barrel may be used. It should be noted the 16 inch 5.56mm barrel uses a mid-length gas system and all others use a standard carbine gas system. All is accomplished at the user level; no armorer is needed to change out the barrels. The barrels are manufactured from machine gun barrel steel and button cut rifling. They are cut with the Mil-Spec 1 turn in 7 inch twist allowing up to 80 grain projectiles to be stabilized. The barrels have chrome plated bore and chambers and are equipped with an A2-style compensator. With Lewis Machine & Tool being a U.S. government contractor for many different parts, they are familiar with what Mil-Spec means and what it takes to achieve it. All barrels manufactured by Lewis Machine & Tool are proof tested with a 70,000 psi proof cartridge and then magnetic particle inspected to insure the barrels are free of stress fractures. When the barrel is installed in the MRP, the barrel is completely free floating. This increases accuracy as well as the air holes in the MRP circulate air to aid in cooling. The removable barrels also enable another innovation: the MRP is a multi-caliber weapon as different caliber barrels can be used. Complete changing of the barrel is accomplished in less than 5 minutes.

The MRP provided for this evaluation came with many enhancements that are all Karl Lewis. Starting with the sights, the rifle was provided with the LMT BUIS (Back Up Iron Sight). This is a fully adjustable rear sight that has been provided to the U.S. Navy and SOCCOM for the MK18 CQB 10.3 inch carbines. The sight is identical to that of the standard M16A2 or M4. The front sight is removable and held on by a nut. It has the traditional triangular shape and square front sight post. Of course, being a Mil-Std 1913 rail, any BUIS can be mounted.

The charging handle has an improved latch that is easier for one to grasp as it is made wider so it is easier to actuate.

The bolt and carrier are also a significant departure from the norm. When Lewis looked at the new design, he looked at the specific operating dynamics of the carbine and how different it is from the rifle. Given the different dynamics, Lewis designed the bolt and carrier to function with that in mind. To begin with, the bolt carrier has had several modifications. Due to the dynamics of the carbine, the bolt unlocks at a faster rate on a carbine length gas system than a full length rifle. Owing to this quicker action, there is still residual pressure in the cartridge case and it is still somewhat expanded when the rifle starts to extract making the extractor and extractor spring work that much harder to extract that cartridge case. It also causes extractor springs to wear quicker than that of the rifle. SOCOM has added rubber O-rings to increase the extractor force to cope with the wear issue. The standard GI M4 has a new and improved extractor spring (copper in color) that is designed specifically for the carbine to increase extractor force. Lewis also redesigned the geometry of the cam track by increasing the dwell time upon unlocking and thus permitting additional time for the residual pressure to drop allowing much easier cartridge extraction. He also added an additional gas relief port to get rid of unneeded gas.

The bolt was also redesigned with durability on mind using proprietary material that is significantly stronger than standard bolt material. Due to its hardness it is more expensive to procure and more expensive to machine than standard bolt steel. The geometry of the locking lugs has been modified as well. There are stress relief cuts that allow more flexing of the lugs to prevent breakage. The extractor has been redesigned as well. The improved “lobster tail” extractor uses two extractor springs instead of one that significantly enhances the reliability of the extractor in adverse conditions. The extractor claw is considerably more aggressive and stronger as well. Like the barrels and as per Mil-Spec, all LMT bolts are proof tested and them magnetic particle inspected.

The lower receiver has many enhancements as well. The stock is the LMT SOPMOD stock and is the stock assembly purchased by USSOCOM and the U.S. Navy for the M4A1 carbines and the MK18 CQB weapons. The stock is triangular in shape and very smooth. There are two removable sling mounting points on the stock as well as a cut-out for a standard GI silent sling. There are two battery compartments that are water resistant tubes placed inside of the stock and there is a removable rubber butt plate as well. The receiver extension is also designed by LMT and has six positions as opposed to the standard M4 which has 4 positions. The provided pistol grip is the Ergo Grip that is extremely comfortable and with the finger grooves is comfortable and makes the rifle stable in the shooting hand in adverse conditions. Also provided on the lower receiver is the Ergo Grip Gapper. This little spacer covers the gap in-between the front of the pistol grip and the trigger guard. LMT’s proprietary ambidextrous selector lever is also provided. This is not just good for left handed shooters but can be just as useful to right handed shooters as well given the tactical situation. Tangodown rail covers were provided on the rails.

The rifle was outfitted with the new EOTech XPS2-2 two dot reticle holographic sight. Extremely compact, this sight uses a single 123 battery and has a battery life is 500 to 600 hours. This sight only requires 2.75 inches of rail space. Along with the sight is the EOTech Generation II 3X magnifier. This comes with a Samson Quickflip tilting mount attached to an A.R.M.S. throw lever mount. When disengaged, the magnifier sits to the right side of the rifle: when engaged for long range shooting it flips back.

Also attached to the rifle was the Insight Tech M3X tactical light with pressure pad activation that was mounted in a Tangodown vertical foregrip. By just removing a spacer, the pressure pad sits in the grip. The grip also is hollow allowing for additional storage.

The magazines chosen for the rifle are the Magpul PMag, one of the finest magazines available anywhere in the world for the Black Rifle. This magazine is a significant reliability enhancement to any member of this family of weapons. The constant curve design allows the shot column to sit in its natural shape and increase feed reliability.

The ammunition for this test was provided by Silver State Armory (SSA). SSA is known for manufacturing some of the highest quality duty and match ammunition in the industry at competitive pricing. Silver State Armory just moved to a state-of-the-art facility in Packwood, Washington where they have a 100 meter underground range and the facility meets United States Department of Defense requirements to manufacture military contract ammunition. They manufacture their own brass. All SSA ammunition is loaded with custom blends of powder geared towards the specific loading. They offer several loadings in 5.56mm, 7.62mm NATO, 6.8SPC and .499 LWRC. They are also one of the only ammunition manufacturers in the United States to manufacture armor piercing rifle ammunition in 5.56mm, 7.62mm NATO and 6.8SPC.

More than 300 rounds of SSA 5.56mm 55gr FMJ rounds were fired through the MRP for function testing and no malfunctions were encountered. There were 200 rounds of SSA 5.56mm 77 grain OTM cartridges fired as well. Groups at 100 yards kept around 1.75 inch groups consistently with the FMJ rounds. All in all, this barrel has had more than 500 rounds through it and as it has broken in the groups had tightened up. First groups fired with the SSA 5.56mm 77 grain OTM were consistent at 1.75 inches. The last groups fired with this ammunition were printing consistently at 1 MOA.

LMT Piston Operated MRP

The industry has gone through a piston craze over the last few years. Although there is no statistical data proving the superiority of piston operation over direct impingement, there has been a market for piston operated weapons in the AR-platform. When asked why LMT began producing piston operated rifles, Karl Lewis simply said “customer demand.” Good enough of an answer.

The versatility of the MRP made it the ideal platform for the piston operated LMT offering. The piston is part of the barrel assembly. The gas block on the barrel has been altered to accept the end cap, piston, operating rod and spring. It is held together as an assembly so the assembly is inserted into the MRP and locked down with the two bolts. The one-piece bolt carrier was modified too for use with the piston. The impact area (key area) of the carrier is machined into the bolt carrier giving strength and durability to the carrier. All the gas relief ports have been eliminated. Skis have been added to the bottom of the rear of the carrier to prevent carrier tilt caused by the off-center movement caused by the impact of the operating rod on the bolt carrier. To remove the piston assembly from the barrel, depress the detent and rotate the end cap and pull outward. Now the operating rod and spring can be removed for maintenance. The piston operated system requires the use of the heavier H2 buffer (two tungsten weights and one steel weight). The MRP piston barrels are offered in both 5.56mm as well as 6.8mm Rem SPC.

Provided for testing was both the 16 inch as well as the 12 inch CQB barrel. More than 300 rounds of Silver State Armory 5.56mm 55gr FMJ ammunition was fired with no malfunctions. More than half of that was fired on fully automatic utilizing a Colt M4 lower receiver. Slightly more recoil and muzzle flip was noticed with the piston operated system

Converting the MRP to Fire 6.8mm Rem SPC

The absolute finest innovation of the MRP is its easy ability to convert to fire a different cartridge. LMT currently makes barrels in 5.56mm and 6.8mm Rem SPC. LMT has also tested calibers in 6.5 Grendal, 5.54x39mm and 7.62x39mm. Provided with the MRP test rifle was the barrel and bolt to convert the rifle to fire the 6.8mm Rem SPC cartridge. The 5.56mm barrel was unbolted and pulled out of the MRP and the 6.8mm barrel put in its place and the bolts torqued down to 140 inch pounds. The bolt was removed from the bolt carrier and replaced with an enhanced bolt chambered for the 6.8mm Rem SPC cartridge. LMT provided four Precision Reflex, Inc. 25-round magazines. Also provided by C Products were five of their steel 25-round magazines.

The first 300 rounds fired were SSA 110 grain Nosler Accu Bond cartridges. No malfunctions were encountered. With this ammunition, the groups at 100 yards remained at 1.25 inches off of a bench. For accuracy, the SSA 115 grain Sierra OTM Match rounds were used. Groups measured at a consistent 1 MOA. Recoil was noticeably more than the 5.56mm but not enough to mention firing on semiautomatic. SSA also manufactures an armor piercing round in 6.8mm Rem SPC. It consists of a pointed carbide core with a machined brass sabot offering an incredible barrier penetration. It penetrates with ease a 1/2-inch thick Mil-A-12560 class 1 armor plate out of a 16 inch barrel at 100 meters at a velocity of 2,800 feet per second.

In research into weapons chambered for the 6.8mm Rem SPC it was noticed there are two different chambers. They are referred to as the spec 1 and type 2 chambers. The spec 1 chamber is the one which has a SAAMI specification and has a .050 freebore. The spec 2 chamber has .100 freebore, which permits longer projectiles (better ballistic coefficient). Additionally, the longer freebore decreases pressure 4-5,000 psi. With a 115 grain projectile, a spec 1 chamber will give 2,425 feet per second and a spec 2 chamber will give a higher 2,575 feet per second. As of this writing a significant number of manufacturers are making their 6.8mm Rem SPC barrels with the spec 2 chamber; however, some remain with the SAAMI spec chamber. This is due to the standardization in chamber drawings. There is a rumor going around that a new chamber specification, which is the spec 2 chamber will be introduced to SAAMI as the 6.8x43mm. As of this writing, only Silver State Armory and one loading in Hornady TAP line is loaded to the spec 2 pressures. Silver State Armory loads both commercial and spec 2 loads. Before shooting spec 2 ammunition in your rifle, consult the rifle manufacturer to determine which chamber your rifle has.

The Lewis Machine and Tool MRP is truly in a category of its own and is the benchmark for the modularity of the M16/M4 weapon system: one receiver, multi-caliber barrels and available in both direct gas as well as piston operated. More caliber offerings are most certainly on the horizon. With all the barrel lengths and calibers offered, the MRP will do just about any job required of it. Whether it is a CQB environment with the 10.5 inch barrel or hunting medium game with the 6.8mm Rem SPC, this one size does fit all. Selective fire versions of the MRP are available to both law enforcement as well as military customers. With the proper tax stamp and compatible state laws, short barreled versions of the MRP can be had by the general shooting community. LMT has been a forerunner in new developments and innovation, which will bring the M16/M4 well into the new decade and beyond.

By Christopher R. Bartocci

In the late 1950s a new rifle was developed that would change the entire concept of the battle rifle. Although the U.S. Ordnance Corps had no vision to see it, history was in the making. Eugene M. Stoner while working for ArmaLite, a division of the Fairchild Engine and Aircraft of Hollywood, California, developed the AR-10. Taking his experience in the aircraft industry he replaced traditional wood stocks with new synthetic materials and changed from a traditional steel receiver to lightweight aircraft aluminum considerably decreasing the weight of the weapon. Another innovation was the use of a direct gas system instead of the traditional piston operating system. His design was very radical for that time. With the M14 nearly already adopted, the 7.62x51mm AR-10 was submitted to compete. As expected, the M14 was adopted but the AR-10 was noticed for being abnormally accurate for an auto-loading rifle. From there the AR-10 was cast into the bottomless scrap heap of the not invented here weapons of the U.S. Ordnance Corps. Although a request from the Air Force would have the AR-10 scaled down to .22 caliber and the birth of the AR-15 would go on to revolutionize the battle rifle and have a more then 50 year legacy of the longest serving U.S. rifle in history, the AR-10 lay dormant. That was until Gene Stoner teamed up with C. Reed Knight Jr. of Knight’s Armament Company (KAC) and went back to work on his AR-10 that he never had quite given up on. However, there had been several improvements to the M16 series and he would carry many of them over to his updated AR-10 and developed the SR-25. The acronym stood for Stoner Rifle and added the 10 from the AR-10 with the 15 from AR-15.

Introduced in the early 1990s the SR-25 shared 60% parts compatibility with the current issue M16A2. Funding for the SR-25 development came through commercial sales. As first introduced, the rifle had a 24 inch Remington 5R rifled barrel. At that time, KAC was the only company Remington would sell these precision barrel blanks to. The Match rifle was designed specifically to fire factory 168 grain open tip match ammunition. With this ammunition Knight guaranteed that every rifle that left his Vero Beach facility would fire at or less than one inch at 100 yards and he was willing to prove it by sending the target with every rifle. The original rifles used AR-10 magazines but Stoner would redesign the magazine and improve it giving it a more familiar M16 look. The rifle used the newly introduced integral rail flat top upper receiver so optics could be mounted in line with the shooters eye. The bolt carrier group would retain the original chrome plating and this would go on to be a KAC trademark. The upper and lower receivers were serialized and fitted for precision fit and the SR-25 had a free floated barrel using a carbon fiber handguard. The rifles were not mass produced and when one thinks of Knight’s Armament Company a standard is set for the finest weapons in the world where state-of-the-art meets old world craftsmanship. Stoner continued to improve his design until his death in 1997. Unfortunately, Stoner never saw his new rifle to be finally accepted by the U.S. military as the Mk11 Mod 0 sniper rifle, which would equip the most elite soldiers and sailors the world would ever know.

The Mk11 had some departures from the original design to meet the SOCCOM requirement. The rifle was designed to fire the M118 and M118LR match grade 7.62x51mm NATO ammunition and the Obermeyer barrel was shortened to 20 inches and equipped with a mount for a quick detachable sound suppressor also developed by Knight’s Armament Company. The 11.35 inch Rail Accessory System free floating handguard provided quad Mil-Std-1913 rails enabling attachment of any given number of accessories including night vision, lasers, tactical lights and bipods. The standard M16A2 stock and pistol grip are used for parts commonality. A flip up front sight was added to the gas block as well as KAC’s fully adjustable back up iron sight was also added. The rifle was equipped with 20-round magazines, a Leupold Vari-X mil dot scope with detachable rings and a Harris bipod. The Mk11 weighs 15.3 pounds unloaded and has an overall length of 45.4 inches long. The Mk11 would see action with U.S. Special Operations troops all over the world.

Knight’s Armament Company is first and foremost a defense contractor so commercial weapons were rare and due to the manufacturing process and quality they are very expensive. However, some did trickle down to the commercial market. In 2009, KAC introduced a new rifle, the SR-25 Enhanced Match Rifle. This rifle is a commercial version of the MK11 with the addition of the new URX free floating handguard that was designed for use on the M110 SASS (Semi Automatic Sniper System), which is replacing the M24 Remington sniper rifle in the U.S. Army.

The 20 inch barrel is the same as the one used on the Mk11. Through the evolution of the SR-25, the upper receiver was originally made from an aluminum extrusion; now the current rifles use forgings. The fired cartridge case deflector is now integral in the receiver rather than attached to the rail. Keeping with the tradition of the AR-10 and Gene Stoners expertise, no forward assist was added to the SR-25 family of weapons. The URX (Upper Receiver Extending) handguard as noted previously is a complete free floating handguard with a built-in folding front sight. When folded it acts as additional rail. The gas block has a section of rail on top of it as well as the mounting bracket for the QD sound suppressor. The rifle was supplied with three rail protectors enabling the rifle to be held and shot without a bipod. The upper receiver was also equipped with the KAC fully adjustable folding back up sight.

The bolt carrier group has gone through changes over the years. KAC has improved upon the chroming process and one of the finest features of the bolt carrier is the captive firing pin retainer pin. The carrier uses the standard M16 carrier key. The bolt has remained very similar to the original design with the major enhancement being to the extractor and ejector.

The lower receiver has most certainly gone through evolutionary changes. The area to the rear of the magazine release was machined down similar to the standard M16 making the button easier to actuate. The original SR-25 used a plastic spring guide, whereas the new rifle has an actual buffer. The standard M16A2 buttstock is used. Added to the left side of the receiver is an ambidextrous magazine release that can be reached by the trigger finger of a left-handed shooter. The trigger is the KAC designed two stage trigger which has an excellent crisp pull. The first stage is 3 pounds and the second breaks at around two pounds. The bolt catch has been redesigned from the original design. Originally it was a standard M16 bolt catch but with heavy use it proved not to be strong enough the take the weight and halt the 7.62mm bolt. KAC developed a stronger bolt catch.

The SR-25 Enhanced Match Rifle weighs 10.4 pounds with an overall length of 39.5 inches. The barrel is 20 inches long. Using GI issue M118LR (175 grain) match ammunition produces a muzzle velocity of 2,560 feet per second. The rifle is supplied with a 20-round magazine and an operator’s manual as well as a safety lock.

The test and evaluation rifle provided was just what I would have expected from Reed Knight. A precision rifle held to the highest craftsmanship and modern manufacturing standards. The rifle was not provided with an optic. Everybody has a different idea of what the best optic is and KAC lets that be up to the customer. Some additional magazines were procured and the rifle was tested with the new Magpul LMag and the C-Products 20-round steel magazines.

The ammunition used for testing was provided by Silver State Armory. Function testing was done with Silver State Armory M80 Ball (SSA10084-150FMJ). Accuracy testing was done with two different Silver State Armory loads. First was the 168 grain Sierra open tip match (SSA10084-OTM) and the second was the 175 grain Sierra open tip match (SSA10084-M118LR). The cartridge cases are manufactured by Silver State Armory to match specifications and their powder blends are proprietary and chosen for the particular load. Silver State Armory is known for their manufacturing of match quality ammunition in 5.56mm, 7.62mm, 6.8mm Rem SPC and a few others. They specialize in military calibers.

The barrel of the rifle was cleaned every 20 rounds with no malfunctions in 140 rounds that were fired. Targets were fired at 100 yards and both the 168 and 175 grain match rounds produced groups that averaged .45 to .75 inches – just as guaranteed by KAC and the target they provided. With the low round count I would expect the rifle to shoot even better if the barrel was broken in. The M110 will be with the U.S. military for quite some time.

The “Black Rifle” has gone through several incremental changes over the last decade. The industry is vast and there is no shortage of accessories and product enhancements. Although most of them are “gadgets,” some have truly been enhancements that lead the weapon platform into clearly new territory and may define the future configurations of this combat proven family of weapons.

In January, 2009, Colt Defense introduced and began shipping their first new model for the law enforcement community in nearly a decade. The LE6940 is truly the “next level” for Colt’s legendary AR-15/M16/M4 family of weapons. What sets this model apart from the rest is that it is built on Colt’s monolithic upper receiver. This receiver provides multiple enhancements to the weapon.

The 1-Piece Upper Receiver

The upper receiver is a truly monolithic design. Many of the so called-monolithic upper receivers in the industry are actually two pieces welded together. The top rail of the rifle offers a continuous rail from the rear of the receiver to the front sight base. This satisfies zero retention and zero repeatability requirements. Optics may be removed and installed with no effect on zero. The 3 and 9 o’clock rails are also rigid and provide the same zero retention. The barrel itself is fully free floated. This offers several enhancements in accuracy, heat control and durability to the weapon. By having a free floated barrel, accuracy is enhanced as there is no heavy piston or handguard to interfere with the harmonics of the barrel. This feature is used on competition rifles and is essential for precision shooting. The receiver also enhances cooling of the weapon and thus durability is also increased. It is unlike many current rail systems which are made of aluminum or steel and attach at the barrel nut as well as the handguard cap that transfers heat from the front sight base (hottest point of the barrel) back into the aluminum receiver. An additional feature of the Colt design is its barrel extension and nut. There is an increase in the contact area between the barrel and receiver to increase accuracy. The barrel nut also does not have to be aligned with the gas tube.

By utilizing the 1-piece upper there is a significant savings of cost and weight compared to purchasing a traditional M4-type carbine. The savings in cost comes from not having to purchase and install an aftermarket rail system as well as a back up iron sight, which are already standard on the LE6940. Experience shows that many military or law enforcement operators will immediately upon receiving an M4-type weapon, remove the handguards and install a rail system and purchase a back up sight.

The LE6940

Colt Defense has taken their new monolithic upper receiver and offered it to Law Enforcement. The LE6940 offers the enhanced monolithic upper receiver with a 16.1 inch M4-profile barrel with the step cut. The barrel is the standard GI 1/7 inch twist chrome lined barrel offering the user the ability to fire the full range of projectile weights. The 16.1 inch barrel is perhaps the optimal carbine length barrel for both accuracy and terminal performance of the 5.56mm cartridge in a carbine configuration. Just like the military weapons, every barrel is subjected to a 70,000 psi proof cartridge and then magnetic particle inspected to insure the barrel is free of stress fractures. The rifle comes equipped with the standard A2 compensator. The upper receiver also has a forward assist and a fired cartridge case deflector.

Another outstanding feature is the introduction of the new folding front sight. Unlike most of the folding front sights on the market, the Colt folding front sight base is pinned in place as opposed to screwed on. Pinning the front sight base is significantly more durable and permanent. Due to the pinning process, the front sight base will not loosen and adversely affect accuracy or reliability. The benefit of the folding front sight is enormous when using optics. The standard front sight base often obstructs the view of optics when mounted on the rail of a flat top upper receiver and the shooter has a significantly better field of view with the front sight folded. Most optics as well will allow co-witnessing between the back up sights and the optic in case the battery was to fail or the optic was to become damaged. The front sight base is equipped with a bayonet lug. The Colt folding front sight is robust and positive locking. Another benefit of having the front sight attached to the barrel is when the barrel moves due to thermal expansion the sight moves with it maintaining zero. The production LE6940 uses a quick detach sling swivel, which can be mounted on either mounting point on both sides of the front of the receiver. The lower handguard, which is removable, requires only the push inward of a detent on the rear of the bottom of the handguard. Once the detent is pushed in, the handguard is slid forward and then pulled down. The rail is more robust, easier to remove.

‘ The LE6940 comes standard with the U.S. Government Issue MaTech back up iron sight that is adjustable for both windage and elevation. The elevation is adjustable up to 600 meters and zeroes the same as the standard M4/M16A2 fully adjustable rear sights. The elevation is calibrated for the drop of the M855 ammunition. Windage is easily adjusted with the standard size windage knob.

The LE6940 comes with a standard M16 bolt carrier and bolt. The bolt is also test fired with a 70,000 psi proof cartridge and then magnetic particle inspected to insure it is free of stress fractures. The extractor incorporates a Mil-Std extractor spring, which increases extraction reliability.

The lower receiver incorporates a change as well. Since the introduction of the Colt Sporter series semiautomatic only rifles in the early 1990s, Colt has used a larger .170 hammer and trigger pin. This was an effort to prevent conversion to automatic fire. Thus with the larger pins, one could not install selective fire components. This proved to be problematic with Colt customers. By not using industry standard .154-inch diameter hammer and trigger pins, many of the enhanced triggers would not be offered to Colt Sporter and Match Target owners. The LE line of Colt semiautomatic only rifles would also use the .170 diameter hammer and trigger pins. The LE6940 is introduced with a lower receiver which goes back to the standard .154 hammer and trigger pins. This is a result of both customer request as well as parts standardization.

The lower receiver is equipped with the standard GI telescopic stock with four positions allowing for individual adjustment. Another new feature incorporated into the LE6940 is the reversible selector lever. If the shooter is left handed, they only have to unscrew the pistol grip screw, remove the pistol grip and, with the hammer cocked slightly, push down on the hammer and remove the selector lever from the left side and reinstall it in the right side.

The Magpul 20-round PMags were used for all function and firing testing. The test and evaluation rifle was fired off of a bench at 100 yards. The ammunition selected for accuracy testing was Black Hills Mk262 Mod1. This is the special operations 77-grain open tip match Sierra projectile and, in this author’s opinion, is the most accurate out-of-the-box 5.56mm available. Groups maintained 1-1/2 inches at 100 yards using a Trijicon ACOG scope. The trigger on this rifle broke at 6 pounds with little creep. For functioning testing, the 1-piece upper receiver was placed on a selective fire M4 lower receiver. More than 1,000 rounds were fired on automatic with no malfunctions encountered. The sample rifle was equipped with a VLTOR Modstock, PMags, Insight Tech Gear M3X tactical light and KAC vertical pistol grip.

Further Development of the 1-Piece Upper Receiver

The Colt monolithic upper receiver has become a standard in most of Colt’s new weapon designs. Given its versatility of design, it may be used on both direct gas operated rifles as well as piston designed weapons. Colt’s prototypes unveiled at November 2008’s Industry Day held by the Secretary of the Army utilized this 1-piece receiver including the ACC-M (direct Gas), APC-M (piston), SCW (direct gas and piston), Hybrid and the Infantry Automatic Rifle.

Colt’s new weapon began shipping out of the Hartford, CT factory in January of 2009. New models are on the horizon in 11.5, 14.5 and possibly even 20-inch barrel lengths. The monolithic rail platform is a for-sure hit due to all the features offered. Police departments will be able to buy a rifle already equipped with a rail and back-up sights instead of purchasing them as accessories. The money saved can be put toward optics and other needed gear.

The Colt CGL (Colt Foregrip Laser)

Along with the T&E LE6940, another new Colt product was found: the new Colt Foregrip Laser. The CGL was a joint venture between Colt Defense and LaserMax, Inc. LaserMax is known to be an industry leader in micro diode technology. A previous government request was for a vertical pistol grip that would combine the laser sight.

The CGL incorporates a vertical pistol grip, laser sight as well as a traveling light in one package. By a selector switch on the rear of the CGL, the unit may be set for the traveling light, off, constant beam laser as well as the pulsating laser. The CGL uses an American Defense QD Auto Lock mount. The CGL is activated by an activation switch on the front of the grip. By squeezing the switch slightly the unit will turn on momentarily. By squeezing all the way in, the unit will be continuously turned on until the switch is depressed and released. The unit is powered by two commercially available AA batteries.

The current offering is a 635nm laser that has an orange color. Constant as well as pulsating modes are available at discretion. Pulsating offers the benefit of battery life extension and is easier for the eye to pick up as it “irritates” the eye so it is more visible. There are several tactical applications for this option to include distinguishing ones laser apart from another. Given there is no play in the lower handguard, the CGL holds an alignment of 1/2 inch at 25 yards. Laser sights are designed for close quarter battle scenarios and not as precision long range targeting devices.

The traveling light is not to be confused with a tactical light. The LED traveling light is designed for low level brightness, which is used to view objects up close such as the floor in front of the operator or objects immediately in front of you. The T&E unit showed this very well. When entering a dark room and activating, the traveling light showed the ground and walls well; when switched to a tactical light, the whole room lit up.

The benefits of laser sights are many. First and foremost it is intimidation. Due to the use of the media, everyone knows if you see a red dot on you something bad is about to happen. The media has conditioned society to react that way to a laser. Laser sights offer law enforcement an option that may prevent them from firing their weapon when without it the outcome may have been quite different. The use of the laser also speeds up reaction and engagement time. It is more efficient to use a laser for quick fire situations than sights. Many times when under these circumstances the operator may not have time to shoulder his weapon and obtain a sight picture. The laser offers the shooter full use of peripheral vision to better know the situation and what is going on around him.

The laser is adjusted by two Allen key screws. An adjustment tool was provided with the CGL. The CGL was mounted to the front of the bottom rail of the LE6940. An Insight Tech Gear Laser Borelight System was placed in the muzzle projecting a laser of the centerline of the bore. The CGL was placed on pulsating laser mode and switched on. The CGL was zeroed with the Laser Borelight System at 15 yards. This distance was chosen because the tactical situations which the CGL truly shines are for engaging targets at close range. The CGL is shipped with one daylight zero target. This is a reflective target that allows the laser to be seen in broad daylight. Nifty idea since most indoor ranges will not allow a high power rifle.

At 15 yards, the laser was shooting within an inch off hand. Accuracy was acceptable and the speed of engagement of targets was enhanced. There were no problems with the CGL. More than 300 rounds were fired with no noticeable change in alignment.

Colt Defense has released a new Black Rifle as well as a new accessory this year. The industry has waited to see more new products from Colt and they will not be disappointed. Although U.S. government contracts must be the priority at Colt Defense, as of this writing, Colt Defense has been producing significant numbers of Law Enforcement and commercial rifles. Recently at AUSA, Colt Defense unveiled several of their new products including alternative operating systems as well as their monolithic upper receiver. Small Arms Review will certainly be on top of these developments as information is released.

(Small Arms Review contributing editor Christopher Bartocci works as a Technical Specialist for Colt Defense LLC. The articles written by this author are of his own research and evaluation and in no way represent those of Colt Defense LLC.)

Throughout the years, flashlights were considered a separate entity from firearms – something to be held in the other hand. Around the time U.S. military personnel entered combat operations in Somalia, troops began to realize it would be advantageous to have the flashlights mounted to the rifle to keep the other hand free to reload the weapon, clear malfunctions or whatever else might need be done. So, troops began to tape small flashlights to the handguards of their weapons. Two specific needs were shown at this point. One was a method to mount accessories to the rifle with some type of rail system. The other was a secure way to mount a flashlight amongst other accessories to the rifle. The first inspired A.R.M.S., Inc. to develop their Rigid Frame System (later evolved into the SIR) and C. Reed Knight, Jr. to introduce his first RIS (Rail Interface System) and later RAS (Rail Adapter System). With the final standardization of the Swan/Mil-Std-1913 rail and the then RIS system, now flashlights could be easily mounted to the handguards of the M16/M4 series of weapons.

In 1988, Insight was founded in a basement workshop. Early products were rail mounted lasers and illuminators. One of the first prestigious contracts for Insight Tech-Gear would come from a revolutionary program of the newly developed United States Special Operations Command.

Illumination 101

There are many applications for illumination in a tactical situation. It may be for illuminating an entire room, outdoor use where higher brightness is needed, or perhaps infrared for covert use. The most common form of light is incandescent. This consists of a bulb utilizing a filament. There are several variations of this type of bulb that make it brighter and have more life. Filament is fairly cheap making it easy to maintain. The filaments used with Xenon gas is somewhat less expensive than the LED (to be discussed later). The tint offered off of a filament bulb has a yellow-orangeish color to it making it a little friendlier for identifying features of a person at a quick glance. Probably the most serious downfall to the bulb is that when this type of power is utilized (70+ Lumens), the bulbs burn pretty hot – enough that if accidentally left on in a nylon bag, it could melt the nylon.

The other and growing popular illumination option is called LED or Light Emitting Diode. This technology became widely available in the late 1990s. This technology, although slightly more expensive, offers major benefits. The diode is much more durable with a life of 50 to 100,000 hours and the LED components are difficult to damage with external shock. LED has overtaken the efficiency standard of incandescent lighting systems. LEDs produce more light per watt than incandescent bulbs. The battery life is slightly better than the incandescent bulb and does not get anywhere near as hot. Due to these factors, it is not necessary to have back-up bulbs on hand. The LED has one minor trade off. They are more sensitive to malfunction under extreme ambient temperatures. There must be a proper heat-sink to maintain operating temperatures. The light from the LED is a bluish color. The bluish color can hide features of a person’s face as well as color of skin identification at a quick glance. Colors in general may be perceived differently with LED illumination that would not be altered with sunlight or incandescent illumination. However another incredibly useful use for the LED is target disorientation. When configured to do so, the LED can function in a strobing manner which when aimed at a target will disorient them and often will give just enough time to subdue the target before they can get their eyes refocused to do harm.

Insight Tech Gear Flashlights and Tactical Lights

Insight Tech Gear offers both incandescent as well as LED flashlights and tactical lights. Many models are manufactured of aluminum and are hard coat anodized for tough handling in all sorts of weather. Insight offers some different hand held LED flashlights. The H1X Proxima uses one Duracell Ultra (123) lithium battery with an LED output of 80 Lumens. This light is compact and could easily fit on one’s pocket or on a utility belt. The sample light put out an incredible amount of light for such a small package. The Proxima has settings for constant light, momentary as well as strobe capabilities. The H2X Arcturus is a rechargeable LED light. The H2X has an LED output of 120+ Lumens and the H3X Regulus has an astonishing 160+ Lumens of output. This model utilizes three Duracell Ultra (123) lithium batteries. All models have an activation button in the rear that activates and selects momentary, constant, strobe and dim settings. The LED flashlight provided for test and evaluation was the H3X Regulus. This LED flashlight can be held as a flashlight or placed on a mount and mounted to a rifle or any other type of long arm. There is a pressure activated button on the rear for moment or continuous illumination. The Regulus has settings for strobe, momentary, lock-out and continuous use of illumination. The LED output is 200+ Lumens of light and is powered by two 123 6volt batteries. The run time for the batteries is approximately 90 minutes on high power versus 400 hours on low power. The case of the light is made from aluminum alloy and is hard coat anodized to a black, tan or olive drab finish.

Additionally, the XTI Procyon is a module which will attach to the rail of a pistol or long arm which puts the LED into a tactical light. This gives a minimum LED output of 125 Lumens. A toggle switch on the rear allows the LED to perform in constant, momentary and strobe modes. There is a significant tactical application to the strobing features whether it be a LED in a flashlight configuration or weapons mounted. The strobing LED light will disorient a suspect for up to 2 seconds. This could take the place of a flashbang grenade (which serves the same purpose but on a much larger scale) under many entry circumstances. When taking a hostile suspect into custody, the strobing light could disorient them long enough to get them in cuffs and stop them from being a threat without the use of pepper spray or deadly physical force. The body is hard coat anodized aluminum for added strength. The rail interface is adjustable to fit any of the currently produced Mil-Std 1913 rails. The sample light was placed on a .45 Auto caliber Beretta Px4 pistol.

Insight has a host of various incandescent illumination lights. The M3 and M3X have a peak output of 90 and 125 Lumens respectively and can be attached to either a handgun or a long arm. This is as simple as switching the back plate. Pistol will utilize toggle steady-on or a contoured pistol remote back plate. For use with a long arm, a long gun back plate is used which has mode switch with three positions (off, mom and on). A pressure pad is plugged into the rear of the back plate.

The X2/X2L Series Xenon tactical light is designed to be installed on rails of sub compact pistols. The activation switch is a toggle style and is powered by a single CR2 3 volt battery. The peak output is 40+ Lumens.

The M2 UTL (Universal Tactical Light) was designed for H&K for use with their USP pistol. This mount is designed specifically for the USP pistol and utilizes two 123 6-volt batteries for a peak output of 90+ Lumens. This was the first rail-mounted tactical light in the industry that offered blinding illumination which was actuated by a single finger and was rail mounted and installed without tools.

The vast majority of the Insight Tech-Gear’s LE/military lines of lights are tactical lights. This means the lights are designed to be mounted on the firearm. There are models specifically for mounting the lights on handguns as well as ones which will mount on any Mil-Std 1913 rail.

The Laser Aiming Module (LAM)

After all U.S. special operations units were brought under one umbrella, one of their first programs in August of 1991 was the OHWS (Offensive Handgun Weapon System). Due to the numerous sidearms utilized by the operators, it was conceived as an offensive weapon system including a pistol, laser aiming module and a suppressor. The pistol part of the competition would come down to Colt and Heckler & Koch with H&K being the winner. The new pistol was designated the MK23 Mod 0.

Insight would be selected as the winner for the LAM (Laser Aiming Module). The LAM would have a focusable visible illuminator, an infrared aiming laser, visible aiming laser, infrared laser illuminator and would be powered by two 123 6-volt batteries. The visible laser is a <5 mW power with a wavelength of 640±40nm and the infrared laser is .05-.10 mW power and has a wavelength of 830±50nm. The Infrared Illuminating Laser has a .15 – .65 mW power and has a wavelength of 830±50nm. Infrared lasers and illumination lasers are used in conjunction with night vision devices. The benefit of this is that nobody other than those wearing the night vision devices will be able to see the laser pointer or the illumination. This is useful for a commander to point out a target to his team or to take out targets quickly and accurately in low level to complete darkness. The visible white light illuminator has a brightness of >60 Lumens.

The LAM weighs 5.0 ounces and has a dial on the left side of the unit to permit the user to select the mode that he wants to use. These modes are IR with IR Illuminator, IR laser pointer only, OFF, VIS laser and VIS laser with Illuminator. There is a toggle switch beneath the unit that with a slight push to the side will get momentary on and all the way to either side will get continuous on. The lasers are adjusted individually by an Allen head wrench. However, the unit comes with an integral adjuster tool which is stowed in the face of the unit above the white light source. At the time of the introduction of the Mk23 Mod 0, there was no standardized rail. H&K developed their own rail and the LAM would mount to the rail and held in place by a thumb screw.

Insight Tactical Laser Aimers/Pointers

Although first applied to handguns, these universal units were fitted to long arms as well. Lasers have proven themselves in both the law enforcement as well as military area of operations. Lasers have many applications. As an aiming device, it enables the user to hit targets from any position without having to use the sights. If a SWAT officer is standing behind a shield, he will be able to reach his firearm around the side of the shield and use the laser to aim. For target identification, commanders are able to mark targets for the team so everyone is after the same guy. Lasers can also be used as intimidation in order to diffuse a situation before deadly force is deployed. Sometimes just the appearance of that dot on the target will be enough for the target to surrender. Another important, but often overlooked application to lasers, is in training. The laser can help a firearms instructor to see what problems the student is having. The laser will not be zeroed to point of aim. The magazine will have dummy rounds randomly placed unknown to the shooter. When the dummy is attempted to fire, the laser will show the instructor if the student is jerking or pulling and to what side. This will assist in corrective action. Many modules combine the laser pointer with the white light source.

Insight initially designed the LAM that grew into several generations of laser and illuminators. The M6 and M6X laser illuminators consist of both a laser and a white light. The white light is a 90+ and 125+ Lumen output light respectively with a 640±40nm laser pointer. They can be used simultaneously or separately. The visible illumination can be focused by rotating the bezel and the laser is adjusted by an Allen key. The back plate is determined by whether the unit will be mounted on a pistol or a long arm. If the unit is to be mounted on a pistol, a back plate with a toggle will be used. Lightly pressing activates the momentary power and all the way continuous is activated. To mount on a long arm, the long arm back plate is utilized. This contains a switch with three positions (off, mom and on). The laser has another switch behind it with settings for off, visible laser, illumination only and visible laser and illumination simultaneously. A pressure pad is plugged into the rear of the back plate. The pressure pad is the attached to the vertical pistol grip of handguard. The sights can be attached either by a Mil-Std 1913 mount, a universal mount or a Rail-Grabber. Options also include Bikini filters in IR, red and opaque.

The X2 Laser tactical light and laser combination is designed to be installed on rails of sub compact pistols. The activation switch is a toggle style and is powered by a single CR2 3-volt battery. The peak output is 40+ Lumens. The laser is again activated with a toggle switch. The visible laser is a <5 mW power with a wavelength of 640±40nm. The laser point of impact is adjusted with an Allen key.

The LBS (Laser Borelight System)

This is one of those products that should be in any armory whether it is LE, military or gun shop. The sample provided for this article was put to use immediately and saves many rounds and a lot of time (especially on a freezing New York February day).

The LBS is a laser boresighting system that is used to boresight optics, lasers, as well as iron sights for 5.56mm, 7.62mm and .50 caliber firearms. This 4.5 ounce device is attached to a mandrel of the appropriate caliber bore and placed in the muzzle of the firearm. The activation dial has four settings (off, goggle, low and pulse). The goggle setting has the Borelight beam operate in a low power mode that is useful with night vision devices for night time zeroing. The low mode has the Borelight operate in a low power mode that is useful in low light conditions. The pulse setting allows the Borelight beam to turn on momentarily when the weapon is dry fired. The laser has a wavelength of 650±30 nm with a peak power of 0.9mW.

The provided test and evaluation M6X was boresighted with the LBS. The sight was placed on a SIR rail system on a Colt M4 carbine. The LBS was placed in the muzzle and the laser sight was adjusted to the boresight. At the range at 25 meters, the projectiles landed less than 1 inch to the left of the point of aim A couple of corrective clicks and done. The provided test and evaluation ISM-V (Integrated Sighting Module-Visible) was mounted on a LWRC M6A1 rifle and the LBS was used to boresight that unit as well. Both the laser and red dot on the ISM-V impacted a little more than an inch to the left at 25 meters. Another quick adjustment and done.

The Integrated Sighting Module

Red dot-type reflex sights have gained overwhelming popularity with military and law enforcement users. Currently, the most popular reflex sights are the AimPoint Comp2 and the new Comp 4 and the Trijicon ACOG reflex sight. The first uses batteries and the other is powered by a tritium lamp. Insight took an approach that uses both an optical reflex sight as well as a laser. Why not put both in one?

The ISM (Integrated Sighting Module) is just that, a combination of both a red dot (<2 MOA) reflex sight as well as a laser. The module fits onto any Mil-Std 1913 rail. Powered by a DL123 battery, the reflex sight features a red dot similar to that of the AimPoint Comp-series military reflex sights. The red dot can be made brighter or dimmer by adjusting the + and – buttons on top of the sight. There are a total of 18 brightness settings. The red dot is adjusted by elevation and windage adjustment screws. The battery life is approximately 1,500 hours for the red dot sight.

Also integrated into the unit is a laser sight. This red laser sight is simultaneously zeroed in when the red dot sight is so there is no need to zero them both. The laser can be activated with a button on the left side of the module or a remote switch can be plugged into the face of the unit. There are two models and the laser is the factor that differentiates between the two. The model provided for test and evaluation was the ISM-V, which the V stands for visible laser. The other model is the ISM-IR, which the IR stands for InfraRed. This model has both visible and IR lasers that are activated in the same manner. The ISM-IR has a switch on the rear of the unit that enables you to select either visible or IR mode. On the standard V model the selector has four settings (off, program, red dot and visible aim). The red dot is activated by pressing and releasing both the + and – buttons. To deactivate unit, press both buttons again. Your last brightness setting will be saved.

The test and evaluation unit was placed on a LWRC M6A1 5.56mm rifle: a piston operated variation of the M4 carbine. The unit was boresighted in at 25 yards with the LBS. When taken out for live fire at 25 yards the point of aim was 1 inch to the left. With a quick rotate of the windage, the weapon was zeroed in perfectly. After the red dot reflex sight was tested, the laser was then tested. As advertised, the laser was shooting to the exact point of aim as the redo dot. More than 500 rounds were fired in testing from several different positions in both semi and fully automatic fire. The sight remained point of aim throughout the shooting session. Off of a bench at 100 yards using Black Hills Mk262 Mod 1 ammunition, the rifle performed consistent 1-3/4 inch groups. The intensity of the red dot was decreased significantly to get a good aim point for accurate firing.

Tactical light, lasers as well as reflex sights have found their way into law enforcement, military as well as commercial weapons. Many companies are branching out to get into the market. Insight Technology has offered competitively priced top of the line products to serve all venues. They have several U.S. military contracts and their equipment is commonly used in the Global War on Terrorism. That is a tribute to the quality and confidence the end users have in their equipment.

Insight Tech Gear
23 Industrial Drive
Londonderry, NH 03053
Phone: (877) 744-4802
Fax: (603) 668-1084
Web: www.insightlights.com

LWRC (Land Warfare Resources Company) began as Leitner-Wise Rifle Company. The company was a research and development firm dedicated to making large bore direct impingement M16-type rifles. The rifle was chambered for the large .499 LWRC cartridge, which gained the interest and a developmental contract by the U.S. Coast Guard. In an attempt at making the .499 more reliable, a short stroke gas piston system was developed; its basic architecture similar to the WWII G43. That was not enough to produce a reliable large bore rifle as the large bore straight walled .499 cartridge was not optimal for feeding or extracting reliably in the M16 receiver. Mid development, the company was faced with a dilemma. There was no future military use for large bore cartridge M16 but saw huge potential in applying the operating system to the NATO standard M4 5.56mm carbine. The company had to figure out a way to introduce something different than the standard rifle. Around this time (early 2000), Heckler & Koch began showing their HKM4, now their 416 weapon system – a piston operated version of the M4 carbine. This is basically an AR18 type piston system. Heckler & Koch concentrated on military and law enforcement sales and decided not to serve the commercial market with their piston-operated rifle. LWRC would not dismiss any potential market or customers. Several prototypes later, they had working rifles. The goal was not to re-invent the wheel and change the entire M4 Carbine, but to make the M4 work cleaner and more efficiently and make it more reliable in adverse conditions. The company was about to go through a major change from an R&D company, to a firearms manufacturer. The company was bought in a management buyout in early 2006 and the company changed the way they conducted business. The company name would remain LWRC, but to reflect the change in management the company would be known as Land Warfare Resources Corporation. In the spring of 2008, LWRC was having difficulty meeting the explosive demand for their rifles. LWRC sought a partner familiar with mass manufacturing for large and small government orders. Majority share of the company was sold to RifTech in an asset buyout. RifTech is a company whose same shareholders own MaTech and several other significant defense product manufacturing companies on the eastern shore of Maryland. LWRC also added International to their name to reflect their efforts to manufacture for allied countries. The new CEO, Mr. Richard Bernstein, former CEO of L3 Communication’s Aerospace division, brings the experience and leadership required to take the company to the next level. Moving forward, the new team at LWRC International feels this partnership between the design and development crew at the old LWRC and the manufacturing experience of the new crew will give the company a competitive edge with potential U.S. and foreign government contracts.

LWRC has been actively competing for weapons contracts. As of this writing, LWRC is entering a submission into the Marine Corps Infantry Automatic Rifle (IAR) program. This is a highly modified version of their proven piston system with the addition of a closed bolt semiautomatic operation and an open bolt fully automatic operation. They will undoubtedly be challenged by Colt Defense, Knights Armament Company, FNMI and H&K. Their rifles are seeing use in all three markets (commercial, law enforcement and military). Their piston system is not unlike any other piston operated firearm. A short-stroke tappet system uses an operating rod that impacts the face of a highly modified carrier key to drive it rearward. Then the operating rod would reciprocate back into the receiver. What is truly unique about the LWRC system is how it releases excess gas from the moving piston. The HK416 bleeds excess gas out the front of the gas block with a valve. The Colt LE1020 bleeds gas from the sides. The LWRC vents it under the handguard. The piston itself directs the excess gases forward preventing any gas from getting near the receiver and bolt group while the operating rod pushes rearward and strikes the carrier key retracting the bolt.

The LWRC system can retrofit an existing impingement gun as well as they make many different rifles of their own. With their own rifles, they use some of the most high-speed accessories to enhance their weapon. They provide the Magpul CTR stock and MIAD adjustable pistol grip. They are provided with Magpul PMags, which are a synthetic magazine that might just be the most durable and reliable M16-type magazine on the market. The rifle looks very much and feels like an issue M4. In fact, the lower receiver is the same.

The three sample LWRC rifles have excellent fit and finish. They were equipped with Magpul CTR stocks (6-poition), enhanced trigger guard and MIAD grip. The safe and fire position was ambidextrous and used hieroglyphic marks similar to H&K. The LWRC piston guns all use the H2 buffer (2 tungsten and 1 steel weight) that are the same weight as a standard rifle buffer. Two rifles each came with a 2-stage match trigger and the third used the standard trigger group. Controls are identical to any other GI M16/M4 family of weapons. The M6A2 rifle was provided with the proprietary LWRC olive green anodized receivers, MIAD pistol grip and CTR stock.

Three of the sample rifles had the LWRC monolithic Rail Adapter System upper receiver with quad Mil-Std 1913 rails. The top rail is removable by two set screws on the face of the rail to enable access to the operating system for maintenance. Like the standard rifles, the M6 series of carbines have a forward assist, fired cartridge case deflector and ejection port dust cover. The M6 and M6A1 use standard front sight bases. The M6A2 is basically the same as the M6A1 with the major change being to the barrel and handguard. The standard front sight assembly is removed in favor of a low profile gas block and the handguard/rail extend past the gas block giving additional length of available rail for mounting accessories. The M6A2 model utilizes a folding front sight. The M6 rifle has standard M4-type removable two piece handguards. The M6 rifle looks nearly identical to that of the standard M4 carbine. As of the 2008 SHOT Show, several manufactures are introducing rail systems that can be used with either the standard gas tube or the various piston operated weapons. This would be the LWRC equivalent to the standard issue M4 carbine. One M6A1 rifle was equipped with a Canadian hammer forged 15.9 inch SFW barrel, Trijicon ACOG sight with a mounted red dot sight. The back-up sight was the Government Issue Matech BUIS. The M6A1 rifle used for test and evaluation was equipped with a 16-inch heavy barrel in the free floating LWRC M6A1 upper receiver. The accessories used on the rifle were an Insight Technology M3X flashlight with a pressure pad activation mounted to a Knights Armament vertical pistol grip, Insight Technology ISM-V red dot/laser sight module and a LaserMax UniMax green laser sight. The fully automatic testing was conducted with this rifle’s upper receiver placed on a Colt M4 lower receiver equipped with a Magpul UBR stock and a H2 buffer.

The bolt carrier has a similar look to the standard M16 but with some changes. First to notice is the carrier key is totally different. The key on the LWRC bolt carrier is hardened super alloy and locked in place by a dovetail fit. The rear of the carrier is flared outward leaving a larger diameter at the rear than the rest of the carrier. The purpose of this is to keep the carrier in alignment with the buffer extension. Due to the use of a piston, when the carrier is struck and it begins to move rearward, it is also moving on a slight downward angle. The flare aligns the carrier with the buffer extension and prevents any damage to the buffer extension from the bottom edge of the carrier. The interface between the piston rod and carrier key is mated with a beveled face of the carrier key and a rounded profile of the piston rod. This keeps the piston rod centered at the moment of impact with the carrier key. Also noted is the removal of the gas exhaust ports. Due to this being a piston system, there is no gas to be bled off. This also will prevent any dirt from entering the inside of the carrier. Originally, the carriers were black and coated with a DuPont Teflon finish. As of April 9, 2007, LWRC changed to a Teflon Nickel coating that is matte gold in color. This finish has excellent lubricating properties and is more durable than the previous DuPont Teflon coating. For $29.95 and a return of your black carrier, LWRC will send you out a new carrier with the updated finish.

LWRC has also introduced a new bolt for their family of weapons. The LWRC Advanced Combat Bolt looks similar to the Lewis Machine and Tool Enhanced Bolt but with a few changes. Like the LMT bolt, the LWRC Raptor extractor has a “lobster tail” appearance with dual buffered extractor springs. There are no undercuts on the lugs adjacent to the extractor. The bolt is manufactured from “Unobtanium” (i.e., proprietary metal LWRC does not want you to know about). The bolts can be used in standard direct gas/impingement guns as well. The bolts from LWRC all use gas rings. The purpose is ease of assembly and it keeps the bolt in good alignment with the barrel extension.

LWRC offers a wide variety of barrel lengths including 8, 10.5, 14.5 and 16.1 inches. All rifles feature the M4-type extended feed ramps on the barrel extension as well as the upper receiver. Both civilian/law enforcement semi-auto only as well as selective fire rifles are available. LWRC sells the rifles in both black and flat dark earth colors. The M6A2 DMR (Designated Marksmanship Rifle) is a match grade rifle equipped with either a Magpul PRS (Precision Rifle Stock) or a UBR (Utility Battle Rifle) stock. The barrel is match grade and comes in 16 and 18 inches in length and to add to the solid feel of the rifle, the Magpul MIAD pistol grip and Enhanced Trigger Guard. The trigger is upgraded to a Rock River two-stage match trigger. This model is offered in 5.56x45mm as well as 6.8 SPC.

The M6, M6A1 and M6A2 are offered with an array of barrel lengths suited for nearly any combat scenario. With the market place being what it is, the LWRC rifles can literally have most any design update, BUIS, optic, flashlight, pistol grip and stock enhances and trigger upgrades as that of the standard M16 and M4 carbines.

All the test rifles functioned flawlessly without lubrication. The M6A1 rifle was fired more than 1,500 rounds. More than half was fully automatic fire. The accuracy was up to par with any M4-type carbine and the overall system was flawless. Three Beta C-Mags were fired to test reliability. All three magazines were fired in a single 100-round burst. Again, the rifle functioned flawlessly. During testing it was a conscious decision not to use lubrication as this author believes the Teflon Nickel coating of the bolt and carrier significantly enhanced the performance without lubrication. The finish on the bolt carrier made only a rag necessary to clean it. It has been my experience that piston operated versions of the M16/M4 weapon system experience slightly sharper recoil than the direct gas guns and the LWRC guns were no exception. This sharper recoil is the result of the piston striking the top of the carrier key and that pushes downward on the bottom rear of the bolt carrier. This changes the felt recoil of the normal in-line construction of the direct gas guns. With the direct gas guns, the recoil energy is distributed evenly in the rear of the inside of the bolt carrier driving in rearward in line with the buffer and the shooters shoulder.

Noted arms expert, trainer and former Delta Operator Larry Vickers endorses the LWRC family of weapons stating he feels this is the best piston operated M16 variant commercially available. This is a very bold statement of the quality of the LWRC family of weapons. LWRCI is certainly a company to be taken seriously for potential military contract competition. The management of LWRCI has clearly demonstrated they are committed to quality, durability and reliability. Is the piston operated rifle the future? That is unknown. Many companies have come out with piston operated rifles due to it being customer driven. Thus far the U.S. Army has made its position very clear on the issue believing that the existing M4 and its proven direct gas system are working well and are the weapon of choice by our American warfighter. Nevertheless, there my be an open competition for the U.S. armed forces next battle rifle over the next few years. There is no question the battle proven M16A4 and M4 carbine will be the baseline and the weapons the competitors will try to beat and those weapons to challenge the mainstay will undoubtedly be piston operated rifles. You can rest assure piston operated entries will be entered by Heckler & Koch, Colt and FNMI. But do not be surprised to see a LWRC International entry to compete for the gold.

The concept of a PDW (Personal Defense Weapon) is to provide personal firepower in between that of a pistol and a carbine. Several attempts have been made: the 5.7x28mm caliber by FN, the 4.6x30mm by Heckler & Koch as well as the 6x35mm by Knight’s Armament Company. The U.S. military has asked from time to time for lighter and more compact versions of the M4/M16. Colt was involved with one in particular, showed up with it and then told it was nice but they really do not have a requirement for it.

Around 1997, Colt’s Manufacturing Company, Inc. went to work on a new project. Colt was approached by Michael Harris of Special Analytical Services (SAS) with a concept of a mini-assault rifle that would have the purpose of being a personal defense weapon as well as have law enforcement and military applications. By design, the intent of the MARS was to replace the 9mm pistol as well as numerous variations of submachine guns. A Colt development team, headed by Engineer James Taylor, set out to bring Harris’ concept to life. The MARS was designed with the concept of having a smaller and lighter weapon that could win a fight against an AK47. The MARS was, and still is, different from the FN and the H&K cartridges. The 5.7×28 and 4.6x30mm cartridges primary purpose was to defeat body armor. Unfortunately after they defeat the armor, they have very poor terminal performance. They are ballistically very similar to the .22 Winchester Magnum cartridges. Harris believed the MARS could replace 80% of all pistols and submachine guns as well as up to 20% of rifles and carbines.

The 5.56x30mm Cartridge

The MARS fired a newly developed 5.56x30mm cartridge. Ballistically, the 5.56x30mm MARS cartridge is very similar to the .221 Fireball. The new cartridge was developed to enhance accuracy and range over current cartridges such as the 9mm NATO and 5.7x28mm. The MARS cartridge exploits the high energy densities of modern ball powders. The 5.56x30mm cartridge would be effective out to 300+ meters. Another goal was to enhance lethality over existing small submachine guns. The 5.56x30mm cartridge would have the penetration capabilities of the 5.7x28mm cartridge but have increased lethality over that as well as 9mm NATO ammunition. The MARS cartridge was a wildcat cartridge that was never made in quantity. All 5.56x30mm ammunition was hand loaded by Michael Harris. The cartridge began with the standard 5.56x45mm cartridge case. It was trimmed down and formed in a custom die to the proper dimensions of the 5.56x30mm cartridge. It was loaded with a 55gr full metal jacket boat tail (M193 Ball bullet), 62gr full metal jacket boat tail with penetrator core (M855/SS109 bullet) as well as a tracer bullet. Using the 55-grain bullet, the MARS rifle would fire it at a muzzle velocity of 2,620 fps out of its 10-inch barrel with muzzle energy of 838 ft/lbs. There was a problem found with the pressure levels within the 5.56x30mm MARS cartridge as the case was prone to bulge or rupture.

The MARS cartridge can be loaded to any mission specific configuration which could include hollow and soft point bullets as well as ball and armor-piercing. It is loaded up with magnum pistol-type ball propellant, which is burned at rifle pressures to achieve higher velocity in its short 10.5 inch barrel. The MARS is battlesight zeroed in at 200 meters and the path of the bullet stays within approximately 3 inches of the line of sight. The 5.56x30mm bullet will penetrate a Kevlar helmet and vest at 300 meters. The MARS was also chambered for the 9x30mm MARS cartridge which was a necked down 10mm magnum cartridge case.

There were three prototypes made during the course of development. The upper and lower receiver, bolt and stock assembly were all shortened. According to Colt’s MARS Project Manager Jim Taylor, every component was basically walked through the manufacturing process. The components nearly all started out life as standard M4 components and were modified to MARS specifications. Due to the shorter 5.56x30mm cartridge, a new magazine was created. This enabled the magazine well to be shorter contributing to the shorter upper and lower receiver. The magazine was made from a standard GI 30-round magazine. Material was removed from the middle and welded together. The follower was cut down as well. The magazine was merely a prototype and very clumsy but worked well for the testing and proof of concept.

The overall length of the collapsible stock was shorter than the standard carbine. The front portion of the stock just ahead of the locking latch was removed of an inch. Due to the shorter buffer tube a modified buffer was designed. It was similar in design to the standard buffer, just shorter. Due to the decrease in length, two tungsten weights were used and with the use of tungsten, the smaller buffer was nearly identical in weight to the standard H buffer.

The bolt carrier was shortened overall, particularly the rear behind the bolt carrier key and used a modified firing pin. The carrier key was shortened and only has one carrier key screw. The firing pin was shortened and the rear head was removed. The rear of the firing pin is visible from the top of the bolt carrier. The bolt is the standard rifle bolt assembly.

The lower receiver was modified to make it more compact and to accept the shorter magazine. The magazine well was cut in the middle, material removed and electron beam welded back together to accept the shorter magazine. This is easily seen in the prototype due to the bottom of the magazine well not being straight. The new process of electron beam welding allowed the fabrication of prototypes for a relatively modest cost. According to Colt project leader Jim Taylor, the MARS rifle may have been the first extensive use of electron beam welding for firearms prototyping. Due to the desire to maintain the bolt design and existing cam path in the bolt carrier, the MARS rifle had to modify the location of the hammer/trigger pins, selector lever and the automatic sear had to be moved slightly rearward. On the prototype MARS lower receivers, the fire control holes were drilled as per mil-spec for the M4 carbine. The original holes had to be plugged and new ones drilled in the proper location. Due to the hammer being moved rearward, a large steel roll pin was installed to prevent damage to the lower receiver if the trigger was pulled without the upper receiver installed. If the hammer was to fall on the aluminum receiver it would damage the receiver because it would hit the inside of the receiver on an angle rather than square. Due to the firing pin head being shortened, a pocket was cut into the hammer where it will strike the firing pin. This pocket allows the hammer to strike the firing pin square rather than on an angle. Also, if the disconnector was to fail, the firing pin could not protrude through the breech face to detonate the primer unless the bolt was locked. Additionally, if the hammer was to ride the bolt, there would not be sufficient energy to fire the cartridge. The MARS was designed to make use of as many existing machines and fixtures as possible to minimize the potential cost of going into production.

The upper receiver was made shorter as well. The upper receiver was cut right in front of the fired cartridge case deflector, material removed and electron beam welded back together. Additionally the ejection port dust cover was shortened. Standard handguards were used as well as the gas tube. The bayonet lug was removed from the front sight assembly. The 10-inch barrel uses the standard 1/7 inch twist and has the standard A2 compensator. The top of the barrel is stamped “MARS” to denote the caliber.

Preliminary Colt testing of the MARS indicated some highly desirable characteristics. Although relatively small, the weapon pointed like a rifle. The MARS equipped with a 1.5x optical sight firing low impulse 5.56x30mm cartridges at a relatively low cyclic rate appeared to many who fired it to be one of the easiest weapons to learn how to shoot. In hindsight, it appeared the use of the proprietary 5.56x30mm cartridge was an impediment to selling the weapon. Colt wanted to have a proprietary cartridge. Perhaps a more suitable solution would have been to go with the already currently available .221 Remington cartridge. With modern propellants, the .221 Remington cartridge may have been loaded to achieve the goals set out by Harris and Taylor for this proof of concept, and to do it without chamber pressure problems.

MARS was patented on October 27, 1998 (U.S. Patent Number 5,827,992) by Colt engineer James Taylor and Michael Harris (founder of Specialized Analytical Services). Unfortunately the MARS never found acceptance and never entered production. The main interest in the MARS was by the Israelis as a possible replacement for their police Uzi SMG. This was exactly the type of market the MARS was designed for. The production numbers that were discussed would have been 2,000 guns per year for a term of 10 years. Due to this low number of units versus the cost to tool up for the MARS, Colt decided against going into production. Colt had also felt that introducing a new compact firearm would hinder sales of their M16A2/M4 carbine variations.

I would like to thank Project Leader Mr. Jim Taylor for his assistance with this article by providing first hand knowledge of this program. I would also like to thank Colt Defense for providing access to photograph this interesting prototype weapon.

(Small Arms Review contributing editor Christopher Bartocci works as a Technical Specialist for Colt Defense LLC. The articles written by this author are of his own research and evaluation and in no way represent those of Colt Defense LLC.)

World War II brought the submachine gun into prominence with many armies. First being used successfully on a large scale by Germany during the war, Russia, England and eventfully the United States developed their own. It was just as quickly seen the ineffectiveness of the pistol cartridge on the battle field, especially compared to the new intermediate cartridges. Soon after the war, the SMG would be decommissioned throughout the world in favor of intermediate caliber assault rifles.

The SMG did not entirely disappear; they filled a role in law enforcement and in military special operations units. As a military weapon, it was effective under controlled conditions such as close quarter battle as well as when suppressed fire was needed. However, the biggest customer for the SMG was to become law enforcement. The SMG fit their area of operations perfectly. First, it dealt with the issues of over-penetration in the nation’s cities and kept compatibility with the ammunition police officers used in their sidearms. Police were not restricted as the military was in what type of ammunition they could use. By using modern high performance jacketed hollow point ammunition the 9mm NATO cartridge was quite effective and did not suffer from the over penetration and lack of stopping power as the military ball round. The SMG offered SWAT teams a significant amount of firepower in a small package. The first truly successful SMG to be used world-wide came out of Israel: the Uzi SMG – an open bolt selective fire SMG. The next, and the most successful SMG of all time, was the Heckler & Koch MP5. The MP5 would be the standard SMG in use by both military and law enforcement throughout the world. The MP5 was basically a scaled down version of the 7.62x51mm G3 assault rifle. Although the MP5 was a great success, the 7.62x51mm and 5.56x45mm H&K rifles never achieved popularity with U.S. law enforcement. The rifle and carbines of choice were the Colt M16/AR-15 series.

Colt decided that they were losing out on an entire market in the early 1980s. They realized they controlled the rifle and carbine markets in the U.S. but they offered nothing to fill the need for police who needed the lower powered pistol cartridges that were best used in urban environments. Consequently, they set out to design their own SMG and the project for the Colt SMG was given to their Senior Engineer, Henry “Hank” Tatro. With the knowledge that the M16/AR-15 is considered by many to be the finest human engineered small arm in the world (i.e. most ergonomic: controls all within reach of the shooter’s hand without the hand ever leaving the pistol grip and speed of reloading), it only made sense to base it off of the M16. Another viable reason for this is that law enforcement personnel are often made up of armed forces veterans who had already trained, and were familiar with, the weapon system. Additionally, since most of the departments used M16/AR-15 rifles and carbines, there would be little, if any, transitional training. The controls and procedures for loading, unloading, firing, disassembly and cleaning would be identical for the rifles, carbines and well as the SMG.

Since the SMG was to be chambered for the 9mm NATO caliber pistol cartridge, it was initially thought there was no need for a locking system and the weapon would utilize a blow back operation. Initial prototype SMGs would be open bolt. During testing by Tatro, it was discovered that the open bolt mechanism was not as desirable as a closed bolt for two main reasons. First was the concern for safety. If the SMG was to be dropped or jarred sharply on its butt, there was a better than average chance the bolt would travel rearward just far enough to pick up a cartridge from the magazine and chamber and fire it, resulting in an accidental discharge. According to designer Henry Tatro, clearing malfunctions could be dangerous as well. Additionally, ammunition/primer sensitivity could cause safety issues. Lastly, accuracy was decreased. Early prototype Colt SMGs utilized an M1911-style grip safety on the back of the pistol grip. Once the open bolt system was dropped, the grip safety went along with it.

The finalized SMG would be released in 1985 and would be based off the Colt “Commando” carbine utilizing a standard M16 upper receiver without the forward assist. The cam pin slot as well as the gas tube hole in the face of the receiver was omitted. Standard field sights were used with a special designed rear sight aperture. One aperture was for 0-50meters and the other was for 50 meters and farther out. Standard carbine handguards were used with a single heat shield in each.

The barrels were 10.5 inches long and utilized the standard birdcage flash suppressor. The barrels were chrome plated and designed specifically for the 9mm NATO cartridge (FMJ RN, high power). Each barrel was proof tested with a high pressure cartridge and then magnetic particle inspected like their 5.56mm counterparts. The barrel would employ the standard front sight assembly of the carbine.

Since the new SMG was not gas operated, the bolt had to be completely redesigned. The bolt/carrier would be manufactured from a single piece of steel with the breech face machined into the face of the carrier. Original prototypes used a standard 5.56mm extractor but when they went into production a specific 9mm extractor was made. Due to these firing from the blow back method of operation, weight had to be added to the bolt to give higher mass to delay the bolt from opening before the bullet left the barrel. This weight was pinned into the rear of the bolt. Another significant change was the firing pin. The firing pin only had one head and utilized a firing pin spring decreasing weight and mass of the firing pin. Due to the much softer primers used in pistol ammunition, the lighter weight and firing spring were used to prevent accidental discharges from the inertia of the firing pin striking the primer when the bolt closed on a loaded chamber.

The lower receiver would actually be a standard M16/AR-15 lower receiver with a telescopic stock. The main changes would be to the buffer and magazine well. The buffer had to be changed to slow down the cyclic rate of fire. If a standard carbine buffer was used, the cyclic rate would be well over 1,250 rounds per minute. This rate of fire is excessive to control as well as being destructive to the weapon. By developing a heavier buffer (2-piece steel), the cyclic rate was decreased to under 1,000 rounds per minute. Ammunition is a significant factor in cyclic rate as well. Additionally, if a lower cyclic rate was desired, Colt offered a hydraulic buffer which would decrease the rate even further to around 650 to 850 rounds per minute. These models were denoted by a HB suffix on the end of the model number. Another modification to the lower receiver was the redesign of the hammer/trigger pins; making them out of stainless steel to increase their strength due to the pounding of the heavy cyclic rate of the SMG. The hammer pin in particular would break with heavy full-auto fire. This change (hammer/trigger pin is nickel plated for identification purposes) significantly enhanced the durability of this pin for use in the 9mm SMG.

The magazine well had to be modified to accept the significantly shorter 9mm magazine. To keep with parts commonality the standard magazine well was used. Early prototype SMGs utilized a one-piece magazine well adapter. This early design had problems with tolerancing and was not consistent in fit. Production weapons utilized a magazine well with two inserts with the rear insert containing the ejector. An extended bolt catch was used so the rear of the magazine follower would trip the catch to hold the bolt open on the last shot. This insert was pinned in place using a roll pin. The forward insert contained the feed ramp that would guide the cartridge from the magazine into the chamber. This was also pinned in place. This was a good way to do this because it allowed the lower receiver to easily be converted back to 5.56mm by simply removing the three roll pins and replacing the bolt catch. In 2001, Colt changed back to a one-piece insert designed and patented by Colt Model Product Development Engineer Art Daigle (U. S. Patent No. 6,072,352). Mr. Daigle designed this adapter for his own rifle prior to his employment at Colt. He had a receiver that he modified with the two-piece magazine well conversion. He would use this receiver to fire both 9mm and 5.56mm, so the two inserts were removed when he wanted to fire 5.56mm. As he kept re-installing the inserts, the holes in the receiver would “woller” and become oversized. He felt there had to be a better way so that his receiver would not be further damaged. He designed the one-piece adapter and Colt adopted his design in 2001. The first generation was held in place by a lock inside the adapter. A hex screw was tightened and two pins would move outward on the front of the adapter locking the adapter into place. This worked very well for occasional use but there was one problem with the design: when the end user would get hold of it, they would tighten the screw down so tight that the inside of the magazine well would bend or crack. The current production model is pinned in place. The present design is identical to the first one designed by Mr. Daigle, but the lock mechanism was removed and the adapter would be held in by roll pins. This adapter could as well be removed and the carbine turned back into the 5.56mm caliber. This design also eliminated Colt from needing an additional bolt catch specific for the 9mm SMG and carbines. The one-piece adapter has a lever installed that is lifted upward by the standard bolt catch.

The magazine is based on the Uzi magazine. In fact, Uzi magazines may be converted for use in the Colt SMG by cutting out the mag catch notch in the left side. Colt designed their own magazine for the production guns. This included a 20 and a 32-round magazine with witness holes in the side. This double column/double feed magazine was always considered the weapon’s weak link as it was for the Uzi. Due to the design, if the mag was to be dropped on its base, some or all of the cartridges could pop out of the magazine. This fault was cured in other SMGs by changing the way the magazine feeds. Instead of the bolt picking one round off each side of the magazine (double feed), it would pick it up from a central single location (single feed) similar to that of semi-auto pistol magazines (Beretta M9 and SIG Sauer P226, for example). Colt is currently looking at updating their magazine to incorporate this double column and single feed design.

The final design would be the R0635. This was the standard LE version that would fire semiautomatic and in full automatic mode. The R0639 was the same weapon but with a 3-round burst instead of automatic. Additionally, Colt manufactured a 7-inch barrel version of the SMG (R0633) known as the “Briefcase” SMG. This model has been discontinued. As the guns went into circulation one more improvement was made. A gas block was added to the ejection port cover. This was not a cartridge case deflector. Rather, this block prevented gas and unburnt powder from striking the shooter in the face. It was made of a polymer deflector that slid on the ejection port dust cover rod. A modified/cut down ejection port cover was placed next to that. This could be installed on any 9mm gun.

The Commercial 9mm Carbines

As with all the previous rifles and carbines, the 9mm was offered for commercial sale. The first was the R6540; the AR-15 9mm carbine. This was a standard AR-15 carbine with a 16-inch barrel. The carbine used the larger diameter semiautomatic only upper and lower receiver with a standard semiautomatic only trigger group with a newly designed semiautomatic only hammer. This new hammer was designed by Henry Tatro and on April 21, 1987, his “Safety Device Preventing Conversion To Full Automatic Firing” was patented (U. S. Patent No. 4,658,702). This hammer was to prevent slam fire if the disconnector was to fail whether by malfunction or intentional attempt to convert the weapon to automatic fire. The forward ramp on the hammer would catch on the underside of the bolt carrier, catching the carrier and preventing it from chambering a cartridge.

The next evolution of the 9mm carbine was the Colt Sporter Lightweight model R6430 incorporating several changes. Colt omitted the telescopic stock in favor of a fixed stock, the bayonet lug was removed, the fire control group was changed to the larger .170 inch diameter hammer/trigger pins to prevent fully-automatic fire control parts from being installed, and the addition of the pinned-in automatic sear block.

With the passage of the 1994 Assault Weapon Ban, Colt, by law, had to make an additional change to stay in production of commercial rifles; they had to omit the flash suppressor. The Colt Match Lightweight Model MT6430 was introduced.

Current production is the AR6450 of Colt’s Law Enforcement Only line of weapons. This version uses standard mil-spec small pin upper and lower receivers. There is no automatic sear block but additional aluminum has been left inside the receiver. That, along with the use of the large diameter (.170 inch) hammer and trigger pins, prevent conversion to full automatic. The carbine has a 16-inch barrel with flash suppressor and bayonet lug. Marked on the right side of the magazine well is “Restricted Law Enforcement/Government Use Only.”

Conclusions

The Colt 9mm SMG has served many law enforcement agencies well including the U.S. Drug Enforcement Administration, U.S. Department of Energy as well as the U.S. Marine Corps. The SMG never achieved great success nor its potential. Those who use it like it, especially departments that also utilize M16 rifles or M4 carbines. They can switch to the 9mm SMG with no transitional training and not have to learn a new weapon such as agencies utilizing the M4 carbine and MP5 SMG. These have completely different operational differences and the muscle memory from training is compromised with the use of different weapon systems.