V-Line Industries, has just announced the introduction of their newly re-designed Top Draw “pistol safe” Security Case. The new Top Draw is now stronger and even more pry resistant than previous models. It also now has a classic slimmer design. Measuring 12” x 9” x 2.5” deep, the new Top Draw is still large enough to accommodate two handguns with a shipping weight of 10 lbs. V-Line has exaggerated the clamshell design so that the door folds over the body, encompassing it to prevent a prying attack. An inner flange has been added to allow the lock bolt to lock into the body of the case. A 3/8” thick steel lock block welded to the cover guides and strengthens the lock bolt. The new Top Draw features the Simplex(tm) push button lock provides quick and easy access, with a programmable combination. The continuous hinge is staked and welded on one end to prevent pin removal. Foam lining on the top and bottom of the interior holds and protects contents securely in place. The new cases are available in gloss black or ivory powder coated finish, accented with gold tone pinstripe and logo design. V-Line’s new Top Draw model 2912-S is a California-approved firearms safety device that meets the requirements of California Penal Code Section 12088 and the regulations issued thereunder. An optional mounting bracket is available to enable the Top Draw to be used in more than one location. For more information on this and other V-Line products contact V-Line Industries, Dept. SAR, 370 Easy Street, Simi Valley, CA 93065. Phone: 1-805-520-4987. Fax: 1-805-520-6470. Their web site is www.vlineind.com.

REPLICA MK-19 AUTOMATIC 40MM GRENADE LAUNCHER

IRAC, long known for their exacting replicas of full-auto firearms, has now introduced maybe their most exciting new model. The MK-19 Automatic 40MM Grenade Launcher. The MK-19 replica was designed and built using a real MK-19 as a model. This full-size replica is CNC machined from cast aluminum and steel like all other IRAC replicas and is no light weight toy. The replica is as complete as possible with side feed shoot, opening top cover, rear replica sight, spade grips, butterfly spring loaded trigger and charging handles. Also available is the IRAC replica of the MK-64 Cradle Mount with the ammo can mounting plate on the side and a tapered pintle pin. There is also a 10 link dummy ammo belt available. Both the mount and the ammo belt will be offered at an extra cost. The MK-19, like most of IRAC’s replica machine guns, is available in two models. One is a Static Model and the other is a Simulated-Fire Model. The Static Display Model is for show and display for dressing up and completing the looks of a military vehicle. The Simulated-Fire Model is for the person that wants to display their MK-19 as well as make a lot of noise. It uses the IRAC Sim-Fire System which uses oxygen and propane to produce the sound of the real gun, but does not fire any type of ammo or blanks. This is what makes the IRAC Replica Machine Guns classified as Non-Guns as they cannot be made to fire live or blank ammo. For more information contact IRAC, Inc., Dept. SAR, 219-B Pioneer Blvd., Springboro, OH 45066. Phone or Fax: 1-937-743-2240. Web Site: www.iracinc.com.

MAUSER 98 STOCK WITH BUILT-IN SCOPE MOUNT

Advanced Technology, Inc., now announces a new Mauser 98 Stock with Built-In Scope Mount which fits large ring, 7mm or 8mm Mausers 98s with a Standard Bent bolt. Partial list includes German K-98s, Czech VZ-24s, Yugo 24/27s, Yugo 48/48As, Turkish 1903/1937/1938/1946. etc… This new shooter’s design stock has a built-in weaver scope mount for multiple positioning of rifle scopes, a comfortable trigger pull, ergonomic forearm grip, rubber butt pad to reduce recoil and sling swivels studs. This new stock is proudly made in the USA of indestructible, glass-filled nylon. No gunsmithing or modification is requires for large ring, standard bent bolt Mausers. To rear mount a scope, “wide arc” or straight bolt Mausers must be converted to bent bolt. Advanced Technology also offers a Mauser bolt handle to convert to bent bolt in only seven simple steps. The new stock will not fit M38/M96 6.5 x 55 or small ring Mausers. Suggested retail for the new Mauser stock is only $89.99. For more information contact Advanced Technology, Inc., Dept. SAR, 102 Fieldview Drive #400, Versailles, KY 40383. Phone: 1-859-873-9877. Fax: 1-859-873-6229. Their web site is www.atigunstocks.com.

AR-15/M-16 M-4 IN .22 LONG RIFLE

Kuehl Precision Firearms now has a complete M-4 upper that is a dedicated .22 long rifle unit. The new upper use a modified Atchisson .22 kit as a basis for the unit. The design of the Atchisson AR-15/M-16 .22 conversion kit places the .22 LR bolt face 1 1/4” further to the rear than the standard AR-15 design. This allows Kuehl to move the dedicated .22 LR barrel back enough tp produce an M-4 style barrel that is externally only 3/4” longer than the original Colt design. This makes the unit appear to be an exact copy of the 14.5” M-4 but it has a legal 16.1” barrel. Kuehl uses .22 LR barrels that are CNC machined from top quality 4140 or 416 stainless steel barrel blanks with a 1 in 16” twist. A .223 barrel uses a faster twist and a slightly larger bore which translates into excessive leading as well as poor accuracy. The breech end of the Kuehl barrels are designed to mate to the Atchisson .22 LR kit once the chamber adapter is removed and the receiver plate assembly is modified. The barrels are chambered for .22 LR and then air gauged to assure they comply to match grade specs. Finally, the 4140 barrels are finished in a mil-spec manganese phosphate while the 416 stainless steel barrels are left in a natural polished finish. Barrels, when applicable, are equipped with mil-spec forged steel front sight bases properly installed using taper pins. The barrels typically group less than 1” at 50 yards with recommended Federal .22 ammo. Barrel options for other models include 20” 416 SS heavy version and 4140 steel heavy versions in 16” (with either mid or carbine length handguards), a 14.5”/16.1” M-4 unit and NFA versions on 10.5, 8.125 and 5.5625 inch lengths. All units are available in either pre or post ban units. Custom work is also available. The uppers used for the units are FN manufactured A-2 or flat-top A-3 styles and Colt or ASA 9mm styles available as an option. Several handguard options are also available. For more information contact Kuehl Precision Firearms, Dept. SAR, P.O. Box 260, Labiatae, MO 63055. Phone: 1-314-330-2666. Web site: www.kuehlprecisionfirearms.com.

Ted Nugent has been a tireless fighter in the never-ending war to retain our 2nd Amendment Rights and our American hunting traditions for several years. He is often at the center of controversy, refusing to back down to those driven by political correctness and taking the lead for common sense. His latest weapon to assist (and enlist) in these battles is his new book God, Guns, & Rock ‘N’ Roll.

This New York Times Best Seller consists of 315 pages of insight and experiences of the Legendary Motor City Madman that go from the stage, to the woods, to the range and everywhere in between. He invites the reader to into all aspects of his life, both public and private. Ted shares many of his trials and tribulations that reinforce his passion for the traditional American values present at the birth of our great Nation and the necessity for holding them dear to this day.

He is an accomplished shooter in many disciplines and in several chapters he emphasizes the necessity for practice, practice and more practice. He chronicles a few amazing shots with a variety of firearms that would be nothing short of unbelievable in most circumstances and he gives all credit to familiarity with the gun (and sometimes a little luck can’t hurt either).

Being more than proficient in the disciplines of archery, handgun shooting, rifle and shotgun shooting, is not enough to satisfy the ballistic hunger of Mr. Nugent. Of one of his real shooting passions is his love for the machine gun. Let me assure you that he is not just a casual fan of Sir Hiram Maxim’s invention, but is actually a serious enthusiast who never declines the opportunity to hose a backstop whenever possible. Just in case you are still unclear of his interest in our particular field of weaponry, I offer the following quote from Chapter 6; “The rapid sequential pulsation’s of an M16 held tight in my hands, virtually spitting out a torrent of lead, is truly ballistic heaven. My idea of a rainbow is an arch of flowing brass over my shoulder, piling up at my feet ‘til the barrel glows a sunrise orange and someone forces me to stop. Full auto is music to my ears and a sensual serenade to every bone, muscle and nerve in my body.” There are 36 more chapters of high-octane insight in this book.

Having sold more than thirty million records has not jaded Ted in any way. He remains very active in all aspects of firearms rights, the right (and responsibility) to self-defense, and youth education. He is the founder of Ted Nugent’s Kamp for Kids, and he is active in the Law Enforcement community. To call him an activist for the Second Amendment would be like calling the Mississippi River an irrigation ditch.

He is not one to just give lip service and he actually walks the walk in his quest to stay connected to the land and game so many died to provide us with. As a matter of fact he does not buy any meat at all, and only feeds his family with the bounty of his own hunts. You will be happy to know that no one in the Nugent household is going to bed tonight with hunger pains. I highly recommend this book.

The Complete AR-15/M16 Sourcebook
Revised & Updated Edition
By Duncan Long
ISBN 0-87364-687-8
Paladin Press, Inc.
Gunbarrel Tech Center
7077 Winchester Circle
Boulder, CO 80301
$40.00

True to his usual fashion, Duncan Long has provided the firearms community with another great book destined to reside in every serious reference collection. At over 325 pages, The Complete AR-15/M16 Sourcebook, covers all aspects of this rifle from it’s early beginnings to the most current configurations. Other than the obvious subject matter you would expect such as Operation, Cleaning, Troubleshooting, etc, chapters include: Failures, Problems and Solutions; Grenades, Launchers and Ammunition; Innovations, Spin-offs and Copycats; Selective-Fire Conversions and much more.

Many of the common variants of the AR-15/M16 are discussed in great length and detail as well as several of the lesser known versions and relatives such as the M231 Port Firing Weapon, the CMG-2, the XM106, the Colt ACR and many more. Several photographs and drawings are included in each chapter.

There is a giant section dedicated to accessories that range from bayonets to butt stocks and virtually everything in-between. Items include factory options as well as the immense pool of “after-market” parts and accessories.

This book is one of the most complete works I have yet to see relating to the “Black Rifle.” A beginner can easily become proficient in building and maintaining his AR-15/M16 with the assistance of this book, and those already well versed may be surprised at the amount of information they can learn about these guns as well. There is no doubt in my mind that this book has something to offer anyone with even a remote interest in these rifles.

The lower receiver is the part of this rifle that is considered by the Bureau of Alcohol, Tobacco and Firearms to be “the firearm”. This is the part the pistol grip is connected to and carries all the model information and serial numbers. In order to purchase the lower receiver, whether it is part of a complete rifle or as a stand-alone item you must fill out an ATF form 4473 (yellow sheet). If you wish to purchase a lower receiver from an out of state source you must go through a licensed gun dealer.

Every other part of the AR-15 can be purchased direct from dealers, distributors and manufacturers with no local dealer required. The other parts are not regulated. This being the case, that one lower receiver can be transformed into almost any configuration with a simple phone call to one of the several AR-15 parts dealers in this very publication. These new parts can be delivered directly to your home and assembled into your “new” rifle at your convenience.

After you flip through these pages and decide what you want your “new” rifle to look like, you are going to need to find a local RKI in the AR-15 field. (Reasonably Knowledgeable Individual is a phrase coined by Dan Shea back in the old days of Machine Gun News Magazine and makes reference to someone with an above average knowledge in their particular field without having to wear the “Expert” title or to carry any of the excess baggage that comes with that title.) It would also be wise to purchase some of the many books written about the AR-15.

Your next mission will be to obtain the tools necessary to disassemble your rifle from its current configuration and to install the new parts. Your configuration change can be very simple, as in changing only the furniture to go from the early SP1 look to the newer A2 style and this would requite far less tools than swapping barrels on your existing upper receiver. You don’t need to purchase every gunsmithing tool in one shot but you should look into the correct tools necessary each time you modify your gun.

If you are going to just swap furniture, all you really need may be a screwdriver, an allen wrench and a good strong handgrip. If you are going to buy a new upper receiver and leave the original lower receiver alone, you may not need any tools at all. If you are going to change out your trigger group to a newer 2-stage trigger, or add a new double wall gas tube, or re-barrel your original upper you will need a good set of punches, barrel blocks, special wrenches and lots of patience at first. If you are going to purchase a stripped lower receiver and assemble it from scratch to get started, you are going to need even more specialty tools to complete the assembly.

Everyone skimps a little on the correct tools at first but it is important to remember that you are working on a firearm here with a fair value. The correct tools will allow you to work on it with a minimal amount of problems and that translates into fewer scratches and other “whoop’s”. Having the correct tools also make the project much easier to complete. These tools are readily available from the advertisers in these pages and most of the regular AR-15 parts suppliers carry a full line of these specialty tools in inventory. They can also assist you in learning what tools you may need for each application.

When you are changing the configuration of your rifle it is important to remember that just because almost any part will interchange between guns, the final product may not be legal without prior registration with BATF, or it may not be legal at all. If you start out with a pre-ban “assault rifle” you can avoid many legal hassles associated with “manufacturing a post-ban assault rifle”. Just having the pre-ban rifle to start with allows you to purchase barrels with bayonet lugs and flash hiders. If you start with a post-ban rifle, it must remain in a post-ban configuration such as no collapsing stock, bayonet lug or flash hider. Most of the parts suppliers now carry almost identical parts kits that will fit either category to keep you on the right side of the law. Just make sure that you mention to the supplier which rifle you are starting with.

Another configuration problem you should be aware of is maintaining the correct legal barrel length. If you are starting with a 20” barreled, full size pre-ban rifle, you can buy a carbine parts kit and install a 16” barrel and collapsible stock but the barrel can not be shorter than 16”. Almost every parts dealer sells barrels and barreled upper receivers as short as 10”, and yes they would look pretty darn sexy on your new carbine, but this would change the status of your firearm to an illegal short barreled rifle. These short uppers are sold primarily as machine gun replacement barrels where barrel length is not an issue. Should you wish to install one of these on your semi-auto, pre-ban rifle you may do so, but you need to fill out a BATF Form 1 (see Small Arms Review Vol. 1 No. 10) and have it approved prior to ordering the short barrel. Without doing so the mere possession of the short barrel combined with possession of a semi lower receiver can constitute possession of an unregistered short barreled rifle.

If you should desire the look of a short barrel but don’t want the expense of registering the gun as a short barreled rifle you can always purchase the short barrel with a permanently attached flash hider that brings the total barrel length to over 16”. Permanently attached means just that, permanent. A little red Loc-Tite® will not do the trick here. Most are at a minimum silver soldered, and I always drill, blind pin and tig them just to be absolutely certain it is not coming off.

You also want to be aware of the differences between some problematic M16 parts that can be interchange with your AR-15 parts and also cause legal problems. Just as serious as the barrel length, the mere possession of an M16 trigger, sear, bolt carrier, hammer or disconnector combined with possession of a semi auto AR-15 lower can constitute possession of an unregistered machine gun. You don’t want to go there. Make sure you specify to the parts dealer that you are building a SEMI and again, whether it is a POST BAN rifle or a PRE BAN rifle.

The photos placed on the pages with this column represent just a small sampling of the many configurations possible to have with the same lower receiver. These photos were taken on a few different ones. Some of the hand guards or flash hiders don’t necessarily match the correct upper receiver’s to emulate originals, but you can build any combination you wish. The sky is the limit. Of course, there is no guarantee that you won’t like all the configurations and you even many want to own them all at once. This means several lower receivers and much more expense but, hey, who is sweating the details. We all have to start somewhere. Have fun and be safe.

Parts Sources

Cherokee Accessories
Cheek Pieces
2128 Farril Ave.
Dept. SAR
Union City CA 94587
(510)471-5770
www.cheekpieces.com

HGW
Handguards
424 W. Orchard Way
Dept. SAR
Gilbert, AZ 85233
(480)699-9898

Bushmaster Firearms
AR-15 Parts & Tools
999 Roosevelt Trail
Dept. SAR
Windham, ME 04062
www.bushmaster.com

DPMS
AR-15 Parts & Tools
13983 Industry Ave.
Dept. SAR
Becker, MN 55308
(763)261-5600
www.dpmsinc.com

J&T Distributing
AR-15 Parts & Tools
Box 430
Dept. SAR
Winchester, KY 40391
(859)-745-1757
www.jtdistributing.com

M&A Parts
AR-15 Parts & Tools
P.O. Box 32
Dept. SAR
Lake Zurich, IL 60047
(847)550-8246
www.m-aparts.com

GG&G
Mounts and Rails
3602 E. 42nd Stravenue
Dept. SAR
Tucson, AZ 85713
(520)748-7167
www.gggaz.com

Set up on its three folding metal legs, or tied to a convenient tree or other support by the two cloth flaps on either end of the mine, the Claymore could be aimed like a shotgun. When fired by its battery pack firing device, the M18 Claymore would blast its fragments out in a fan-shaped swarm. The beaten zone of the blast fan of the M18 Claymore was 2 meters high and 30 meters wide at a range of 30 meters. The fragments remained dangerous out to over 200 meters in front of the weapon.

Type classified by the Army in 1959, the M18 Claymore was found to have a number of shortcomings when used by the troops. With a short time a modified weapon, the M18A1 Claymore became standard issue. It has remained standard issue in the US arsenal today.

The M18A1 Claymore’s body is a glass-filled polystyrene plastic molding produced in two parts. The rectangular mine body is curved outwards towards it’s front in order to control the spread of the fragmentation when the mine is fired. Inside the front portion of the mine body is the fragmentation matrix consisting of 700 steel balls held in place with a plastic resin.

The rear of the mine body holds the charge of C-4 explosive. Detonation of the C-4 blasts the fragmentation outwards in an expanding arc with a velocity of about 3,000 feet per second (914 m/s. The design of the Claymore’s body is such that the spread of the fragmentation remains in a 60 degree fan-shaped beaten zone 2 meters high and 50 meters wide at a distance of 50 meters from the point of detonation. This area of maximum effectiveness is called the killing zone of the mine and is one of the significant improvements of the M18A1 over the earlier M18 model.

Within the killing zone of an M18A1 Claymore, the fragmentation has a high enough velocity to penetrate a standard US Army armored vest. And additional area of moderate effectiveness extends outward from the mine to a distance of 250 meters. The area of moderate effectiveness is also wider than the killing area and covers an arc 90 degrees to the right and left of the center of the killing zone.

Because of the blast of explosive when a Claymore is fired, all personnel must be undercover when within 100 meters of the mine and no one should be within 16 meters of the point of detonation. With the 16 meter danger area of a Claymore, the backblast of the explosive can cause concussion injuries of personnel, even when they are under cover.

Even when friendly personnel are undercover and at a proper distance, the power of a Claymore going off can be staggering. In a large ambush, where a number of Claymores are fired at one time, the effect is incredible, even when the operators know what is coming. During one PRU ambush operation in Vietnam, the SEAL advisor had over a dozen M18A1 Claymores laid out, and fired them all in a single shot.

“The mines going off sounded like an ARC LIGHT strike (B-52s w/500 lb bombs). Then my PRUs opened up, covering the entire area with a swath of fire. As the firing stopped, there was only dust and a ringing kind of silence.”

Mike Boynton USN (Ret.) Excerpted from “Hunters and Shooters,” Edited by Bill Fawcett. Avon Books: New York. 1995. Page 122

Just about all of the troops who used the Claymore mine liked it. The sudden blast of firepower coming out from a Claymore, or a line of Claymores, could wipe out an incoming group of enemy forces, or cause them to break up in confusion where they could be picked off one by one.

One of the primary uses of the Claymore was for area defense. Positions such as firebases, hilltops, or even just a few holes in the ground and some cover, could be quickly defended by a ring of Claymores. Another very popular use for the Claymore was as an ambush weapon. When properly laid out and aimed, the Claymore could literally sweep an area clear of vegetation, and any personnel who might be there.

The Claymore comes complete in a bandoleer with everything necessary to employ it. The firing system supplied is electrical and includes an M4 blasting cap, an M6 special electric cap attached to 100 feet of firing wire, and a squeeze-type M57 firing generator intended to fire a single cap.

The Claymore can be set up with the M4 blasting cap inserted into either of the cap wells at the top of the mine’s body and secured in place with the screw plugs provided. The 100 feet 30.48 m) of firing wire attached to the cap is unwound from it’s spool out to the firing position. At the position, the shorting plug is removed from the firing wire and the wire’s end plugged into the M57 firing device, also called the “clacker”.

The M57 clacker has a safety bale that prevents the operating handle from being depressed unintentionally. Moving the safety bale on the firing device allows the handle to be squeezed, firing the mine. To test the firing circuit of the Claymore without firing it, an M40 test set is supplied, one per case of mines. The bandoleer of the mine kit containing the M40 test set is marked by a green tag on the shoulder strap of the bag.

The M40 test set itself is a simple green box that has a socket to accept the M57 firing device at one end and a plug intended for the M4 blasting cap assembly at the other end. By placing the M40 test set into the circuit, the firing system can be tested by squeezing the firing device. If the circuit is sound, a visible light will flash in the test set without setting off the cap. Simply removing the test set and plugging the M4’s wire into the M57 firing device readies the Claymore for firing.

In the humid and corrosive environment of Vietnam, even testing a setup M18A1 Claymore didn’t guarantee the mine would go off. Even mines that tested positive seemed to have a mind of their own on occasion. During one operation in the T-10 area of the Rung Sat Special Zone, a squad of SEALs had laid out an ambush for a number of VC thought to be operating in the area. As a group of 10 to 15 armed VC walked into the kill zone of the ambush, the SEAL officer in charge prepared to trigger the ambush.

“Whispering, I said, “Claymore!” The VC were right there, 30 feet away. We would have had them cold. We wouldn’t have had to fire a shot. Only the damned Claymores didn’t go off. We cranked them two or three more times and they still didn’t go off. I couldn’t believe it. Still on all fours, I said, “Open up,” to the Stoner man and the whole squad started shooting…

… we called in slicks and left in style, guns blazing and the Seawolves hosing the place down. We tried the Claymores one last time before the helos came in. The damned things went off. Lesson: explosives can be unreliable so you’d better have a backup plan.”

Captain Rick Woolard USN (Ret.) Excerpted from “Hunters and Shooters,” Edited by Bill Fawcett. Avon Books: New York. 1995. Page 238

Even with the occasional disappointment, the M18A1 Claymore mine earned itself a solid place in the US arsenal. Use of the mine was only limited by the operator’s imagination. Claymore’s were used as boobytraps, base defense, and as a counter-ambush device when a group of US forces were trying to break contact with an pursuing enemy force. For this kind of use, a prepared Claymore would be carried by the squad, outfitted with a non-electric firing system and a 30-second time delay.

The chased squad could quickly emplace the Claymore to cover the path behind them. Pulling the fuse igniter on the Claymore would start the delay and the squad would pull out. As the pursuing VC would come after the squad, they would often run right into the killing area of the mine as the Claymore detonated. The simple act of setting up the Claymore and pulling the fuse actually takes longer to describe than to do.

Some applications of the Claymore worked better than others, Some just never worked at all. One young officer had the idea of lining the sides of a truck with Claymore mines, just the thing to break up a VC ambush. But even with a heavy lining of sandbags, and an armored cab, the truck would only stand up to one such firing before being turned into a twisted pile of junk. And it was very hard to find a soldier who was willing to sit, even in an armored cab, and allow a bunch of Claymore mines to go off all around him.

Probably the biggest compliment to the efficiency of the Claymore mine is the fact that it is the most copied directional mine in the world. Even the Viet Cong worked hard in their jungle workshops to turn out their versions of the Claymore. The VC DH-10 directional fragmentation mine was around a foot in diameter and weighed over 30 pounds. But it could blast its cut-up steel rod fragmentation out to over 200 meters and take out personnel. Closer in, the DH-10 could destroy vehicles and even bring down helicopters.

TECHNICAL DATA
M18A1 Claymore mine

TYPE: Directional antipersonnel fragmentation mine

IDENTIFYING COLOR CODE: Olive drab body

CONTAINER MATERIAL: Fiberglass filled polystyrene plastic

FILLER: C4

METHOD OF ACTUATION: Military blasting cap or primacord; Command detonated with the M57 firing device and M4 electric blasting cap; Remote detonated with a military blasting cap or primacord and a suitable firing device

EFFECTS: Blast drives 700 10.5 grain (0.68 g) steel spheres out in a 60 degree fan-shaped sheaf (arc) from the point of detonation

AREA OF EFFECT: (16 m) Blast radius from C4 explosion; Highly effective fragmentation in an area 55 yds (50 m) wide by 2.7 yds (2.5 m) high, 55 yds (50 m) in front of the point of detonation

LENGTH: 8.5 (21.6 cm) M18A1 Mine; 4 in (10.2 cm) M57 Firing device; 100 feet (30.48 m) firing wire M4 blasting cap

WIDTH (DIAMETER): 1.38 in (3.5 cm) M18A1 Mine; 1.35 in (3.4 cm) M57 Firing device

HEIGHT: 3.25 in (8.3 cm) M18A1 Mine w/legs folded; 3.25 in (8.3 cm) M57 Firing device

EFFECTIVE RANGE: 109 yds (100 m)

MAXIMUM RANGE: 273 yds (250 m) Forward danger radius; USE Local defense of fixed installations and forward areas. Antipersonnel/antivehicular ambushes and directional minefields

At the end of WWII in 1945, exotic and resource-rich French Indochina, consisting of what is today Laos, Cambodia and Vietnam, had been under French control for more than a half century. Even the Japanese invaders had allowed a puppet French regime during the war. Despite diplomatic pressure from America and military threat from the growing communist/nationalist movement known as the Viet Minh, Paris was not about to let go of what was rightly considered to be the most valuable of its colonies. In one particularly dramatic incident in mid-November 1946, French naval, air and ground forces responded to escalating guerrilla attacks by bombarding the northern port city of Haiphong, killing an estimated 6,000 Vietnamese civilians.

Building on resentment caused by this and other incidents, in a radio broadcast on the 21st of December 1946, Ho Chi Minh called for nationwide resistance. The man whose name was to become synonymous with tenacious guerrilla warfare, told his countrymen that although the coming war would be long and hard, in the end “we are bound to win.”

Everything under the sun

Southeast Asia was awash in all sorts of small arms at the time, a legacy of years of Allied fighting against the Japanese. These were readily available for arming all sorts of tribal, ethnic and political factions and Ho lost no time in building up his forces.

According to contemporary estimates by the American OSS (Office of Strategic Services – direct predecessor to the CIA), the communist Viet Minh irregulars, scattered around the full length of Vietnam, numbered approximately 100,000 by early 1947. Additionally, Ho’s regular army under Vo Nguyen Giap consisted of more than 60,000 troops concentrated in what was then known as Tonkin – later North Vietnam.

“The Democratic Republic of Vietnam Army (Viet Minh) is supplied with an assortment of weapons and equipment of various makes and models. Virtually all materiel is from foreign sources, principally Communist China and the Soviet Union. Considerable materiel of French, British, Japanese and United States origin has also been acquired since WWII, initially from abandoned stocks and later by capture.” From U.S. Army Handbook for Vietnam, 1962

Substantial quantities of arms and ammunition were directly provided by China, Vietnam’s ancient northern border enemy that had formed a convenient alliance with fellow communist Ho Chi Minh. China also supplied large numbers of “advisors” to train Giap’s largely peasant forces and most of the Viet Minh regular and guerrilla units were led by native Vietnamese officers battle hardened in the war against Japan.

Land, Air and Sea

Although the French clearly had their hands full in trying to re-establish military and economic control over their reluctant subjects, the picture wasn’t all that bleak. By March of 1947 France had more than 90,000 fighters in Vietnam and 11,000 reinforcements were on their way. France enjoyed total air superiority and its naval forces were both strong and versatile. Understandably reluctant to build a native Indochinese military force that might one day turn against them, most were ethnic Frenchmen or colonial troops from Morocco, Senegal and other parts of the empire.

Also, the famous and colorful Legion Etranger (Foreign Legion) was in country, manning forts, spearheading numerous airborne operations, as well as reinforcing armored assaults and riverborne operations. With its ranks thickly populated by tough and combat-wise veterans of the defeated German Wehrmacht as well as those of many other European armies, La Legion maintained a well-deserved reputation for ferocity and skill at arms.

A Mixed Bag of Weapons

“…the table of equipment for a French battalion in Indochina provided for 624 rifles, 133 submachineguns, 41 BARs, 4 81mm mortars and 8 60mm mortars, while the corresponding battalion of the 304th Viet Minh Division counted 500 rifles, 200 submachine guns, 20 BARs, 4 81mm mortars, 3 recoilless cannon and 3 bazookas.” From Street Without Joy

Since France had been quickly overrun by the Germans in WWII, most of the small arms in the hands of regular and colonial troops were of pre-1941 French design and manufacture. It is likely that the reference to “BARs” quoted above for a French battalion is merely a generic term for automatic rifles/light machine guns. Although both sides made good use of actual American Browning Automatic Rifles which were readily available throughout Southeast Asia, the predominant weapon of this type in Indochina was the “Chatellerault” Model 1924/29. (For in-depth review of the 1924/29 see SAR Volume 4 Number 9)

“The 7.5mm Model 24/29 was a standard pre-World War II French Army weapon that was put back into production after the war. It is an excellent weapon of simple design and unsurpassed ease of maintenance. Although the French refer to this as an automatic rifle, it is a light machine gun by contemporary standards. Its double triggers, large wood forearm, and multiperforated conical flash hider are prime recognition features. There is a large vertical hole in the forearm; this is to adapt the gun to an antiaircraft or vehicular post mount.” From DIA Small Arms ID and Operation Guide

While American .30 and .50 cal. belt-fed Brownings were thoroughly integrated into France’s Indochina forces – mostly on armored vehicles and aircraft generously supplied by Uncle Sam – their standard machine gun was the 7.5mm M1931A. Basically a heavy-barrel upgrade of the Chatellerault designed for use in tanks and fortresses, the 31A is easily recognized by its lack of buttstock and forearm, plus side-mounted box mag or distinctive 150 round drum. Featuring gas operation and a lively cyclic rate of some 750 rpm, there was no provision for quickly changing overheated barrels. The 27.5 pound gun’s mixed reputation for serviceability and combat effectiveness apparently spurred development of the belt-fed AAT Mle 52.

Rifles were usually the simple and sturdy bolt action 7.5mm MAS 36 and folding-stock CR39 carbine, both easily identified by forward-swept operating handle and a prong bayonet stowed in reverse position so that its socket base looked like a second barrel. Additionally, limited quantities of the semiauto 7.5mm MAS 49 made it to Indochina where it proved serviceable, but combat experience influenced design modifications culminating in the MAS 49/56.

French-made submachineguns in use by her forces in Indochina included the very questionable MAS 38 and the superlative MAT 49. The MAS was a handy little machine pistol unfortunately chambered for the pipsqueak 7.65mm Model 1935 handgun cartridge, sometimes called .32 French Long. Quite controllable despite a 600 rpm rate of fire, its effectiveness was severely limited by underpowered ammunition.

On the other hand, the 9mm MAT 49 was a favorite of friend and foe alike because of its soldier-friendly design, excellent reliability and at least decently lethal parabellum cartridge. A compact, sturdy subgun of mostly stampings with machined barrel and bolt featuring simple blowback action, it was easy to shoot and easy to maintain. (See SAR Volume 5 Number 1 for an in depth review of the MAT 49)

Cleverly designed for compact carry with telescoping wire stock and fold-forward magazine housing, the MAT 49 was particularly suited for airborne and armored troop use. Its amenities include a grip safety to preclude accidental discharge when dropped and a spring-loaded firing port dust cover that automatically pops open on firing.

The Viet Minh, and later the Viet Cong, eagerly employed captured MAT 49s and many were subsequently found to have been converted to fire the more-plentiful stocks of communist 7.62 x 25mm pistol and burp gun ammo.

Mon Oncle Americaine

Up to his bearded chin in the Korean War which inconveniently broke out in 1950, Uncle Sam had a keen interest in keeping French Indochina from becoming yet another communist stronghold. To this end, literally millions of tons of American war materiel and hundreds of millions of American tax dollars were lavished on the French. Aircraft, ships, weapons, ammo, communications equipment, food, and countless other categories of aid poured in.

In addition to previously mentioned Browning machineguns, two categories of Yankee small arms were warmly embraced by France’s fighting men in Indochina. The little M1 carbine and its paratroop and select-fire variants were understandably popular with the small framed native troops who found their size, weight and light recoil to fit nicely. Inexplicably, standard-size Europeans of paratroop and other units seemed to be particularly fond of the carbine despite its poor lethality. Ah, the French…

On the other hand, the awesome American recoilless rifles and “bazooka” rocket launchers were clearly outstanding examples of American ingenuity that were particularly well suited for the war in Indochina. Essentially shoulder fired artillery, they provided heavy hit capability even to light infantry units operating in dense jungles. Vehicular convoys and remote outposts could also take advantage of these portable yet brutally effective high explosive stovepipes when facing concentrations of enemy troops.

Au Revois, Indochine

Despite highly effective weaponry from small arms to heavy howitzers, massive and continuing infusions of American aid including tanks and trucks of all kinds, fighter, bomber and transport aircraft providing undisputed mastery of the skies, France lost to peasant fighters of the Viet Minh. Following the disaster at Dien Bien Phu, demoralized French leaders agreed to hand over all of the territory north of Quang Tri above the 17th Parallel to Ho Chi Minh’s communists. In return, all of Giap’s troops in the south were supposed to pull out. Not only did they not leave as promised, they lavishly armed themselves with vast quantities of abandoned Franco-American war booty for the continuing struggle.

20 July 1954 marks both the end of France’s struggle to keep Vietnam in her dwindling empire and the beginning of what would ultimately become America’s longest war.

Primary References:

Advice and Support: The Early Years, US Army Center of Military History, 1983
US Army Area Handbook for Vietnam, 1962
Street Without Joy, Bernard Fall, Stackpole Co., 1964
Small Arms Identification and Operation Guide, Defense Intelligence Agency, 1976

Envisioned by Army Ordnance as a means of giving field-artillery firepower to the infantryman, the M18 was considered to be the largest of the type possible to have the ability to be carried and crewed by one man. Or, as Col. Jim Crossman wrote, it put “rifle accuracy and cannon power on a man’s shoulder”. Weighing approximately 45 pounds versus 2,700 for the 57mm antitank gun and wheeled carriage, it shot a 2-3/4 pound projectile with a muzzle velocity of 1,200 feet per second. It was first demonstrated as the T15 at Aberdeen Proving Grounds in early September 1943 and by early 1945 Ordnance sent guns with demonstration teams to Europe and the Pacific. Initial reports were enthusiastic. It is capable of being fired from the shoulder, off of a built in rear bipod/front monopod arrangement or from the 1917A1 tripod, which is actually the most common means.

There were several shells developed for the M18. The standard HE (high explosive), the HE, AT (high explosive, anti-tank) which used a hollow charge for penetrating armor and a smoke round designated WP for its white phosphorus content. Interestingly, a canister shell was also fielded. This was made of thin sheet metal that contained 133 stacked steel slugs. Upon clearing the muzzle, the sheet metal cover ruptured and exposed the slugs, converting the M18 to a giant shotgun.

The People’s Republic of China (PRC) inherited, or maybe more accurately, captured the design and factory for the Type 36. After World War II, the United States supported the Nationalist Chinese in their war against the communists. Among the help provided were drawings, specifications and technical assistance in producing a version of the M18. When the Nationalists left the mainland for Formosa (Taiwan), they had to abandon the plant to the Reds. The Chicom Type 36 is slightly heavier than the M18 and it has a few smaller differences more based on the manufacturing technology employed than on actual design changes. Like the American version, the Type 36 was usually fired from a tripod though it could be fired from the shoulder as well. An advantage of the Type 36 was that it could fire US or Chicom ammunition whereas the M18 could only use US rounds. The effectiveness of the guns was similar. Effective range was about 500 yards (though some sources say as much as 1,500 yards), armor piercing ability nearly 3 inches and firing rate was between 5 and 8 rounds per minute. By 1968 the M18 and M18A1 were listed in Army Ordnance manuals as being Standard B (limited) issue.

During the wars in Vietnam both the US M18 and the Chicom Type 36 were generously provided in great numbers to allies. The Viet Cong and North Vietnamese Army had plenty and so did the French, the South Koreans and the South Vietnamese as well as US forces.

Just about everyone involved in the Vietnam War put the 57mm recoilless rifle to use, including some naval units on both sides…

An incident told in Brown Water, Black Berets by Lt. Cdr. Thomas J. Cutler, USN, describes the armaments of North Vietnamese Trawler #459 as being 12.7mm deck guns and a 57mm recoilless rifle. These were put to use the night of 15 July, 1967 when the trawler headed for the mouth of the Sa Ky River while trying to run a US blockade and was cornered by several US ships where it came under fire and was destroyed.

The US experimented with the M18 on small craft as well. The Norwegian manufactured NASTY class patrol boats (PTF’s), often manned by SVN LDNN crews advised by US Navy SEALs carried one for use from the bow. Later these were replaced due to backblast concerns. These problems didn’t keep the 57’s from seeing any action. PTF’s were often used to provide transportation and cover for sabotage missions in coastal areas of North Vietnam on their SOG 34 Alpha missions. On one particular mission, an NVN Swatow gunboat ambushed PTF-6 near Hon Me, wounding several South Vietnamese crewmen. With a landing out of the question, they evaded the enemy vessel while destroying a gun emplacement and some buildings with their 40mm, 20mm guns and 57mm recoilless rifles. Along with PTF-3, PTF-6 then turned south and safely headed home.

A MAC-V HQ study in 1965 stated that a favored VC daylight tactic for ambushing riverine craft appeared to be the use of 57mm recoilless rifles supported by small arms fire as opposed to mines. This was due to the accuracy and point target capability of the 57mm. An example of this happened on 07 February, 1966 when VC fired upon the Panamanian ship Lorinda on the Log Tau River in the Rung Sat Special Zone with 57mm recoilless rifle and assorted machinegun fire. The Lorinda made it to its destination but was heavily damaged by this attack. One result of this was the installation of the Mark 48 turret onto Monitor and other riverine craft. This turret on ASPB’s had already received hits from VC 57mm RR fire as well as RPG-2s and RPG-7s with little effect.

Probably one of the best uses for the 57mm RR was devised by the US Special Forces at camp A-103. There were 3 fairly large hills next to the camp and situated on each was a hilltop outpost considered essential to the camp’s security. Since these guns looked down on the camp not only was their accuracy and power appreciated but also the concern for the backblast was essentially removed with the breech venturis pointed at the sky. On the other hand, the VC and NVA took advantage of the mobility of the 57mm RR especially when attacking fixed targets such as A-camps or fire support bases. A typical infantry combat support company was, among others, assigned a 57/75mm recoilless company. These were generally used in a direct fire role in support of larger indirect fire weapons such as rockets and heavy mortars, and usually the last to withdraw when providing cover fire while the heavy weapons packed up and left. The recoilless rifles were also considered to have better accuracy than rockets and were therefore also used against smaller targets such as bunkers and command and communication centers.

Ownership in America today

The US M18 or M18A1 is fairly rare in collector’s hands. Few if any escaped either shipment to a needful ally or the cutting torch. Under US Federal Law, it is classified as a Destructive Device by virtue of its larger than 1/2 inch bore. In speaking with a few enthusiasts, I found that the vast majority of these rifles are built from formerly demilled parts sets. The largest source for these, as well as a good supply of spares is Hayes Outapalik out of Missoula, Montana. Gun Parts Corp/Numrich also lists some parts. Though cases and projectiles are available from several sources, at this time only a brave few are beginning experiments to fire full-bore loads of home rolled rounds. And these are from a tripod with ballistic protection placed around the breech. Most folks own or have made sub-caliber devices (see SAR Vol. 4 #12, Sept 2001). These are available in a surprising variety of chamberings from .22 rimfire up to .50 BMG. The most unusual I heard of was those in 6.5 Carcano. I suppose this makes sense when you realize many of these guns were sold to Italy. A special mention of the .50 BMG unit is required. This actually imparts too much stress to these old guns, especially on the aluminum brackets that hold the tube to the mount whether it is tripod or bipod. The suggested way around this is to either fire the plastic projectile M858 round which has very little recoil, or mount the gun to a recoiling MAG-58 mount without sandbagging the feet. This will allow enough movement to help preserve the rifle’s integrity.

Luckily, there is also an experienced gunsmith out there to put these parts sets together. That’s Steve Carlesco at GSI in New Haven, Connecticut. He has already made several non-firing wall hangers, a few Title 1 subcaliber only rifles and some full bore rewatted 57mm guns. For the latter the customer supplies the pre-approved Form 1.

I should also mention that some experienced individuals in the field of DD’s believe the 57mm recoilless rifle to be dangerous to the shooter. There are a few high wear parts that were intended to be replaced at regular intervals. Without a ready supply of these and a complete record of your gun’s firing history, it is best to listen to the cautions of the experts and follow their recommendations for firing full power rounds if you so choose.

The 57mm recoilless rifle served ably during the cold war. It was portable, powerful and accurate. It gave the infantryman artillery power at a time when similarly powerful field guns weighed thousands of pounds. Yet by the mid-1960’s cheap mass produced Soviet and Chicom RPGs and the US M67 90mm recoilless rifle had rendered the 57 obsolete. For a time though, in a humid simmering cauldron called Vietnam, when the cold war heated up, it was there, doing its duty on both sides of the fence.

Kevin Dockery and Phil Labudde helped immeasurably in the preparation of this article.

Sources:

Part sets, spares, cases and projectiles:
Hayes Outapalik, P.O. Box 8423, Missoula, MT (406) 549-4817
Projectiles and cases only:
Big Sky Surplus LLC, 3018 E. Sinto, Spokane, WA 99202 (509) 535-9486
Gunsmithing, assembly and general advice:
Steve Carlesco, GSI, 41 Main Street, New Haven, CT (203) 467-8437

Working with outside companies such as Honeywell Incorporated, Picatinny came up with a fuze system for the new grenade that was considered a marvel of miniaturization at the time. Even with the small size of the fuze, it was as large as the fragmentation body itself and made up over 50% of the complete projectile. Further studies of the new projectile centered on determining which would be the best way to launch and stabilize it in flight.

Colonel Rene R. Stutler, Chief of Small Arms Research and Development for US Army Ordnance, at his office in the Pentagon had decided that a shoulder fired launcher dedicated to launching the new grenade would be the way the project would go forward. A deputy to Colonel Stutler, Jack Bird, became interested in the grenade launcher project and investigated the idea on his own time.

Taking a piece of pipe that would accept a golf ball, Bird capped off one end and drilled several small holes through the tube’s side. With a spring placed in the tube and a golf ball dropped down over the spring, a stick was used to push the ball down against the pressure of the spring. A nail slipped through one of the holes in the side of the tube held the ball in place on the compressed spring.

Demonstrations of Bird’s “launcher” took place in the central courtyard of the Pentagon. The high arcing trajectory of the golf ball when the cross nail was pulled out demonstrated remarkable accuracy for such a crude device. The high lobbing arc of the ball reminded a number of the onlookers of a nine-iron stroke on a golf course. Jack Bird suggested the program for the new weapon be named after the popular term for a nine-iron at the time, a Niblick. Stutler agreed and Project Niblick was so named.

Once the basic projectile had been established, both a launcher and a means of propelling the grenade were needed. Springfield Armory received funds in June 1952 for its Research and Development Division to conduct a study of various devices to launch the new grenade design. A number of designs were established, built, and tested at Springfield Armory using the various forms of ammunition, now known as the Niblick projectile, coming from Picatinny.

Launchers for the Niblick projectile at Springfield Armory from 1952 into 1955 concentrated on muzzle attachments for the M1 Garand service rifle. These launchers used a blank cartridge to propel a Niblick projectile much like a standard rifle grenade. Designs ranged from a simple tube to a complex 8-round semiautomatic launcher attachment that had a circular magazine holding the projectiles. None of the designs had much advantage over the standard rifle grenade and did not show enough promise for further development.

The Niblick projectile used in most of the muzzle launcher attachments was a drag-stabilized round with an extending skirt that spread out behind the fired projectile. A spin-stabilized Niblick projectile, resembling a fat bullet, was found to have much more promise in terms of accuracy. A cartridge design with a self-contained propellant was needed to further develop the potential of the Niblick projectile.

To fire the very large Niblick projectile from a cartridge case, the standard method of simply filling the case with propellant would not fit the needs of the project. When a standard small arms cartridge is fired, the projectile receives a very violent push from the rapidly burning propellant that gradually lowers in pressure as the projectile moves up the barrel. Using the standard cartridge system with the Niblick projectile would create several recoil problems, eliminating the possibility of a shoulder-launched weapon. Lowering the velocity of the Niblick projectile to allow a shoulder-fired weapon would cause most propellant powders to burn erratically at best, ruining accuracy from round to round, and badly cut back on the effective range of such a system.

During World War II, the Germans had faced a similar question, but for different reasons. The German question was how to build a worthwhile antitank weapon that would be lightweight, use few critical materials, and still have range, accuracy, and lethality. The use of a rocket projectile was ruled out due to an inherent lack of accuracy at long range and a very high consumption of fuel when compared to projectile weight.

A new internal ballistics principle, the “Niederdruck” or high-low pressure system was developed in Germany during WWII and was used by Rheinmetall-Borsig to solve the antitank weapon question. In the high-low pressure system, a relatively small amount of propellant is burned in a high pressure chamber until it reaches a threshold pressure and ruptures a seal. With the seal ruptured, propellant gases bleed through small holes in a metal plate into the low pressure chamber where they bear on the projectile. When fired, pressures in the high pressure chamber reach the 30-40,000 psi range while the low pressure chamber maintains a reasonably steady 3,000 psi. The high pressure chamber allows the propellant to burn completely and efficiently. The low pressure chamber gives the projectile a steady push with the pressure curve having a flat, almost optimal, line.

The steady push of the low pressure portion of the high-low system gives a useful velocity to the projectile but also allows for a more fragile projectile to be used than that of a regular cannon. The low pressure also gives a low recoil impulse but is very consistent for accuracy. The major stress of firing is in the high-pressure chamber so the barrel and resulting support equipment for the weapon can be made much lighter.

The German weapon that fielded the high-low pressure system was the Rheinmetall 8cm Panzerabwehrwerfer 600, or PAW 600. The PAW 600 fired a fin-stabilized, hollow-charge round that would penetrate 5.5 inches (14 cm) of steel, out to an effective range of 600 meters. the smoothbore weapon had a light barrel with only the breech section requiring heavy walls to withstand firing. Set up for action the PAW 600 only weighed some 1,389 pounds (630 kilograms) while a conventional 5-cm Pak 38 cannon weighed 2,205 pounds (1000 kilograms) and only had some 400 meters additional range with much less penetration.

Though considered revolutionary in concept and the only major ballistics advance of the war, the high-low pressure principle was not developed further in the years following World War II. In the 1952-53 time period, Picatinny Arsenal revived the high-low pressure system to propel the Niblick projectile in a self-contained round of ammunition.

The high-low pressure cartridge case was made of aluminum and was unique in its design. The center of the cartridge case was the high pressure chamber, a thick walled extrusion in the center base of the case. Spaced around the side of the high pressure chamber are six precise vent holes. The inside of the high pressure chamber is sealed with a thin brass cup that contains the powder charge and closes off the vent holes. The bottom of the cartridge is closed off with a thick base plug that holds a percussion primer.

When the 330 milligram (5 grain) propellant charge of M9 smokeless powder is ignited by the percussion primer, it builds up a pressure of 35,000 psi while burning. When the 35,000 psi point is reached in the high pressure chamber, the brass seal ruptures and the propellant gases bleed out into the low pressure chamber where they are reduced to a pressure of 3,000 psi. The 3,000 psi pressure moves the projectile up the barrel at a relatively slow rate, maintaining close to full pressure throughout a 14-inch barrel length. The Niblick projectile left a 14-inch barrel with a muzzle velocity of 250 feet per second and a right-hand spin of 3,700 rpm due to the rifled barrel.

The self-contained Niblick round kept a relatively low bore pressure in the launchers when compared to standard ammunition. The only point of high pressure stress when firing the round was taken up by the high-pressure chamber itself. These facts allowed the barrels of the various Project Niblick launchers to be made of aluminum. The low muzzle velocity also prevented any of the launchers from having excessive recoil even though a very large and heavy projectile was being launched for a hand-held weapon.

A number of launchers for Project Niblick were produced at Springfield Armory in 1953 under the direction of the project director, Cyril Moore. Two specific designs of launchers for the Niblick round showed considerable promise. One device was a simple shotgun-like fixture for determining ballistic data for the complete Niblick round. The other launcher was designed to fire six rounds semiautomatically. This was the first of the Project Niblick weapons that was a dedicated, shoulder-fired system. With a large rotating cylinder, the device acted much like a shoulder-fired revolver. Though the idea of semiautomatic fire held promise, the first device was found to be unsuitable for military use.

In the 1954-55 time period, the focus at Springfield Armory was on utilizing the complete Niblick round, though there was still some experimentation with the earlier types of projectiles. At this time, the S-3 launcher, a single-shot, break open, shoulder fired device with a rifled barrel was produced. This device greatly resembled the Federal Laboratories tear gas gun that was popular with police departments at the time but with a more complex sight and a forward hand grip.

A more complicated launcher that had semiautomatic capability was developed and under study by 1955. Identified as the S-6 strip-type shotgun, this was the first weapon to use a semiautomatic capability built into a conventional shotgun format. The S-6 used a harmonica-like strip of three Niblick rounds, each held in its own firing chamber, and feeding through the side of the receiver to give a semiautomatic fire capability. As each round was fired, a spring would drive the strip clip through the receiver until it indexed on the next loaded chamber. This form of launcher met with high approval in the conferences between Springfield Armory and Army Ordnance personnel and effort was put into refining the design.

A second generation semiautomatic S-6 launcher was available within a few months of the first model being accepted for development. Shortcomings from the first S-6 were eliminated in the second generation design. Further work was needed to meet the military needs of such a weapon system and study continued on the design. Other launchers were examined, including large flare-gun like pistols, to use the Niblick round, but none of the designs met with much success.

Later in 1955, the experimental Project Niblick weapons were due to be tested by the Army Infantry Board. Lieutenant Colonel Roy E. Rayle, the Small Arms R&D Chief at Springfield Armory, suggested further development go into another single shot launcher like the earlier S-3 design. Instead of developing a new design, Rayle suggested an already existing pattern, such as the Stevens Model 220 hammerless shotgun with a top-mounted safety and release lever, be modified to fire the Niblick round. The advantages of such a design would be the simplicity of operation and ease of training to recruits.

Lieutenant Colonel Rayle’s suggestion was followed and a second launcher was developed along the lines of the S-3, this one identified as the S-5 shotgun. The S-5 was the first attempt to build a Niblick launcher that followed the lines of a conventional, single-shot, sporting shotgun. The lines of the S-5 remained simple and the mechanism straightforward. Further development continued on the design especially on the shoulder stock and sight configurations. An immediate drawback to the S-5 that limited its appeal to the Army personnel was that the system was single-shot only.

During testing, the S-6 repeating grenade launcher was found to have problems with accuracy and was considered awkward to handle and operate. These problems were quickly traced to the harmonica magazine. A lack of a positive seal between the mouth of the magazine and the rear of the barrel caused propellant gases to slip though the gap. This caused irregular muzzle velocity in the S-6 weapon and greatly limited the firing accuracy of the system. The much simpler S-5 launcher was favored by the Infantry Board testers. A decision was made to try and correct the problems with the S-6 launcher in order to retain the semiautomatic capability while retaining the S-5 design in reserve.

By 1958, the S-6 design had evolved into the T148E1 and T148E2 launchers. The T148E2 design was more complicated than the E1 as it incorporated a break-open design to help seal off the barrel/magazine gap. The greater number of components in the T148E2 design eliminated it from further development in favor of the simpler T148E1 pattern. A limited pilot-line production of 200 T148E1 launchers was conducted between 1 January and 30 June 1958 to supply a number of the weapons for field testing and further evaluation. The gas bleed-off at the chamber/barrel gap still caused an unacceptable loss of accuracy and the T148 project was terminated after 1 July 1960.

A conference of Army and Springfield Armory personnel decided the S-5 design, now known as the XM79, should be reactivated. US Army Infantry Board testing determined that a new sighting system should be designed and a few shortcomings of the XM79 be corrected before acceptance. The new sight design was ready by October 1959 and all XM79 launchers produced up to that point refitted with the correction. On 15 December, 1960, the M79 was officially type-classified and adopted by the US Army. Further production difficulties in producing the complicated rear sight limited weapon availability for some years after adoption.

By 1965, the M79 grenade launcher was in full production and available for issue to all of the services.