The YHM Model 57 is produced in both flat black as well as burnt bronze. Notice this model has a longer extended handguard, which is also an option to the customer.

By Christopher R. Bartocci

The AR business, like any other, has trends that alter the way the weapons are produced to make a more modern updated looking carbine instead of the legacy AR look going back to the early 1960s. Many companies have created unique looking receivers with a much more modern look such as AXTS, San Tan Tactical, Seekins Precision and now the Yankee Hill Machine Model 57. Providing to numerous OEM’s as well as manufacturers of their own weapons is Yankee Hill Machine Co., Inc. of Florence, Massachusetts. Opening their doors in 1951 as a job shop, Yankee Hill Machine (YHM) broke into the gun world in the late 1960s in the form of a government contract making cleaning kits. Around 1998, YHM started to sell complete AR-type rifles in co-op with ZM Weapons. The co-op dissolved and DPMS is now its own company. YHM has manufactured several weapon components for the U.S. military as well making them familiar with military grade quality control.

YHM manufactures a wide variety of components including rifle receivers, back up sights, front sights, rail systems, flash suppressors, lower receiver accessories as well as sound suppressors. They have a very good size selection of complete rifles ranging from entry level to professional. Along with their complete rifle line, they also sell complete upper receivers whether they are stock items or custom items. YHM has earned their reputation in this industry for quality and innovation. One does not have to look very far to see other manufacturers using YHM parts.

The newest entry to the market is the Model 57. To start with, the upper and lower receiver is manufactured from a billet instead of a forging. There are several reasons why this is a benefit over the forging. With a forging, there is very little that can be done to alter the look of the receiver without alteration of the forging die. Another big factor is when there is a buying surge of rifles and components forgings can be very hard to come by. Here in the U.S., there are relatively few forging companies that manufacture for the entire industry. These include Cardinal Forge, Anchor Harvey, Cerro Forge, Martin Marietta and Brass Aluminum Forgings, to mention a few. Many of these have U.S. government contracts with Colt and FN. In some cases receiver forgings that are rejected by those companies find their way into the commercial market as well. Basically, these are standard lower and flat top upper receiver forgings. YHM found during the frenzy of 2012 they had difficulty getting forgings. They wanted to be sure they could build rifles whether there were forgings or not.

Using a billet instead of a forging offers a starting point to allow the manufacturer to sculpture any design they like with the only limitations being the length and the width of the billet. Billets are also much easier to manufacture. The original YHM design arguably mimicked a forged lower (concept design started in January 2013). YHM started to make sure all of their specifications would match any upper throughout the industry. Although the design of their first six prototypes had a very unique look to them, it was too similar to that of a legacy lower so YHM decided on a course in a different direction. At this same time, the YHM engineering department had greatly increased in capability and innovation. YHM knew they could do vastly more with the lower with this new engineering approach as well as improve machining practices. Two more concepts later, YHM arrived with the current Model 57. Once the lower was completed, YHM decided on a whole package. Once this was decided, the YHM engineering team was challenged to come up with an entirely new rifle to show at SHOT Show 2014. By October 2013, YHM had their new billet upper receiver as well.

The Model 57 rifle has an unloaded weight of 7.43 pounds without a magazine. With the stock extended the overall length is 37.5 inches and with it closed is 33.5 inches. The rifle comes with two Magpul Gen 2 PMags and YHM Quick Deploy Q.D.S. sights, which are manufactured from 7075 T6 aircraft grade aluminum. The Model 57 can be purchased in 5.56mm, 300 AAC Blackout (7.62x35mm) and 6.8mm SPC calibers. Finishes are offered in flat black and burnt bronze. The MSRP is $2,195 for the flat black model.

Starting from the rear of the Model 57, the rifle uses a Magpul Commercial Specification CTR stock that is lightweight, durable and has a lock on the stock so it will not inadvertently move without intent. The receiver extension allows the stock six different positions.

The pistol grip is the Magpul MOE or Magpul Original Equipment. This is far more comfortable than the standard Mil-Spec A2 pistol grip and up more of the user’s hand.

The lower receiver is manufactured from a 7075 T6 aircraft grade aluminum billet, the same type of aluminum as the Mil-Spec forgings. The trigger guard is integral into the lower receiver and is oversized to allow for heavy gloves. The magazine well is cut in a unique shape and appears as though the front of the magazine well extends a little more than a standard legacy rifle. During testing of the T&E rifle it was found two magazines would not seat due to this. These were the H&K polymer magazine and the newly introduced Elite Tactical Systems translucent polymer magazines. This bears no reflection on the rifle; these magazines were designed a little different is all. The front of the magazine well has grooves machined into it making it easier and a more solid hold. The rear takedown and front pivot pins are the YHM designed E-Z Pull takedown pins that protrude from the right side of the rifle making field stripping of the rifle considerably easier and faster. The trigger is a two stage trigger that broke at 5 pounds

The upper receiver, also machined from a billet of 7075 T6 aircraft grade aluminum has a very unique sculptured look to it. Machined into the receiver is a forward assist as well as a fired cartridge case deflector. The ejection port has written on the outside the caliber and in the case of the T&E it said “5.56mm NATO.” All YHM firearms now include a caliber marked ejection port dust cover.

The barrel on the T&E rifle is a YHM manufactured 16 inch fluted barrel manufactured from 4140 steel and Melonite QPQ finished. The barrel is referred to as a ball cut barrel and is patterned in such a way so that although material is removed, it retains its original tensile strength. The rifle is offered with a carbine gas system. There are four different barrels offered by YHM: a standard 5.56mm Mil-Spec 1 turn in 7 inch barrel, a 5.56mm barrel with a 1 turn in 9 inch barrel, a 300 AAC Blackout/300 Whisper barrel with a 1 turn in 8 inch twist barrel to accommodate both super and subsonic loads, and a 1 turn in 10 inch 6.8mm SPC barrel. YHM’s ball cut barrel is at this time only available on complete Model 57 rifles. YHM offers both threaded and unthreaded muzzles as well.

The muzzle device was quite interesting called the YHM Slant Series Brake/Comp – a combination of a muzzle brake and compensator. The particular one on the rifle was the YHM-26-MB-A, which can also be bought separately for a MSRP of $70. This device stood out during testing as it did not have the brutal blast on the sides as you would come to expect from a muzzle brake and you could clearly feel it doing its job. Muzzle jump was negligible and although very uniquely and somewhat freaky looking, this muzzle device does an excellent job.

The handguard is the SLR (Slim, Light, Rail)-Slant Series handguard. The top of the rail makes a continuous top rail from the charging handle to the tip of the handguard at the muzzle end. The rail is T-marked so the operator will know the proper placement of the optics or other accessories to maintain zero. This rail is manufactured from 6061-T6 aluminum and is available in midlength as well as rifle length configurations. The rail on the T&E rifle is the midlength (YHM-5145), which has three QD mounts on the front left and right sides and the underside of the handguard. The rail is continuous on the top but the sides and bottom are only 3 inches in length on the front of the handguard. To the rear is smooth and very comfortable to hold. The 12 o’clock position of the handguard accepts customizable Mil-Std 1913 rails. The handguard is 2.18 inches wide and 2.18 inches tall. The handguard does require a proprietary barrel nut. All the necessary components and tools are provided with the handguard for installation. The handguard on the submitted T&E is their Specter Systems – a term coined by YHM that refers to a free floating handguard that extends over/past the gas system/gas block hiding it under the handguard. This also protects the gas system from any damage from the rifle being dropped or any other type of impact.

The rifle comes standard with the YHM Q.D.S. (Quick Deploy Sights) front and rear sights (YHM-5040). These folding backup sights feature a spring loaded automatic deploy system and lock positively in the upright and folded positions. They deploy by a spring loaded button and stow the same way. Both sights are manufactured from 6060-T6 aircraft grade aluminum. The rear sight has the same short and long range dual aperture as the standard A4/M4 rifles and windage is adjusted by a knob. No tools are necessary.

The bolt carrier group is standard Mil-Spec. The carrier group was very well machined and melonite coated. The charging handle has the new YHM tactical latch on it that makes it much easier to manipulate with gloved hands.

The charging handle includes the Tac Latch.

At the same time the new Model 57 arrived, so did some new magazines for testing manufactured by Hexmag. Product design of the Hexmag began in early 2013. Hexmag was incorporated in November of 2013 and began shipping product in March of 2014. The design was done by Adam Schefter, one of the company’s owners.

The material is very similar to other top end magazines that are made of a mix of nylon and fiber materials for strength. The magazine has a series of hexagram shapes on the magazine exterior. According to Hexmag, the grip is the number one benefit and they feel the design was more interesting to look at compared to what else is out there saying the pattern compliments the design and not distracts. The pattern saves on weight and they estimate the weight savings as two 5.56mm rounds per magazine.

Another outstanding feature of this product is the colored follower and the colored lock plate. The base plate has a hexagram shaped hole where the lock plate protrudes and locks the floor plate and magazine base together. No tool is needed to disassemble the magazine. One can use their finger to push inward on the lock plate and slide the floor plate off the magazine body. Both the follower and lock plate are offered in black, orange, green, red, yellow, pink and blue. By changing the color of the lock plate to various colors, this can help the shooter to identify caliber of the cartridges in the magazine as well as projectile types. The magazine itself is offered in black, Flat Dark Earth and olive green.

The market can expect other types of magazines in the future. Hexmag offers a Lifetime Warranty on their magazines. Prior to release, the magazines had been put through a battery of testing including drop testing and compatibility testing. The T&E magazines were subjected to different rifles as well as fully automatic fire.

The YHM Model 57 was tested with numerous magazines to determine compatibility. These magazines included GI aluminum, Magpul PMag, HK High Reliability steel magazine, Hera Arms polymer mag, Lancer AWM, Surefire 60-round and the new Hexmag. These all functioned without issue. The rifle was tested for function with 500 rounds of Black Hills Ammunition .223 Rem 55gr FMJ as well as Federal American Eagle .223 Rem 55gr FMJ. There were no malfunctions. The efficiency of the muzzle brake/compensator was quite noticeable on affecting muzzle jump. The feel of the handguard was quite comfortable. It was nice not having the rail at the rear of the handguard due to how uncomfortable that can be. The Magpul MOE pistol grip is always a winner. The best group shot that day was a .740 inch group by a SWAT Team sniper with Black Hills Ammunition MK262 Mod1 ammunition. This is a 77gr Open Tip Match Round used by SOCOM. It is this authors opinion this is the finest factory produced 5.56mm cartridge in the world. You get a combination of match accuracy and consistent wounding ballistics. Designed by Jeff Hoffman, this round has become the most sought after 5.56mm round in the military as well as foreign military who have had the chance to shoot it with their SOCOM advisors. Black Hills Ammunition makes this ammunition available to the commercial and LE markets as the 5.56mm 77gr OTM in their new manufactured ammunition line.

With all the variations of the Black Rifle you may be thinking, “Not another one!” This is not your typical copy of the M4 carbine – in fact it is the opposite. This rifle sports a new style upper and lower receiver, new free float handguard, excellent fluted barrel, advanced muzzle brake/compensator and more. The only thing this author would have liked to see different is that the gas block to be drilled and pinned in place instead of locked on with set screws.

Everyone is dubious of something that promises to do several tasks well versus a specifically designed product. The underlying concern is that compromises involved with making something adaptable invariably leads to compromises in performance. The Yankee Hill Machine (YHM) Phantom 7.62 Sound Suppressor refutes this assumption. Many civilians agonize over what suppressor to buy due to the cost and time invested in pursuing a BATF tax stamp. At a minimum, upwards of $750 is spent on a quality suppressor along with the $200 for the tax stamp not to mention the bureaucratic paperwork and waiting involved. Yankee Hill’s Phantom 7.62 Sound Suppressor offers the ability to easily function on several different weapons and calibers, thus a flexible alternative to purchasing a suppressor that is relegated to one rifle or caliber.

YHM’s Phantom 7.62 Sound Suppressor is a .30caliber suppressor utilizing Mark White’s Sound Technology, Inc.’s patented (US Patent #7,073,426) baffle design. In fact, the YHM website calls the Phantom 7.62 suppressor a collaborative effort between the two companies. Make no mistake; YHM is the manufacturer, quality control agent, and distributor of the Phantom suppressor. The Phantom 7.62 Sound Suppressor is manufactured from Chrome-Moly steel and features a matte black Parkerized finish. Its overall length is 8.5 inches with a diameter of 1.6 inches and weighs 25ounces.

Besides manufacturing and proofing the Phantom suppressor with Sound Technology’s patented baffle design, YHM created the Phantom Flash Hider (patent pending) muzzle device that enables the quick mounting/dismounting (QD) of the suppressor. Hand tightening is all that is needed with the Phantom Flash Hider to hold the suppressor firmly in place. Conversely the suppressor can easily be removed via hand pressure when no longer needed. The Phantom Flash Hider supports the suppressor in two places helping to ensure bore alignment. A patented gas seal keeps the Phantom Flash Hider threads clean so the suppressor will not bind when removed from a weapon no matter how many rounds are fired. The QD Phantom Flash Hider contributes to the adaptability of the Phantom suppressor. The Phantom Flash Hider is available in 5/8”-24RH, 9/16”-24LH, 9/16”-24RH, and M14mm-1LH thread patterns. By installing multiple Phantom Flash Hiders on different weapons one Phantom suppressor can be utilized on multiple weapons of different calibers. This is what makes the YHM Phantom Sound Suppressor so utilitarian by enabling the 7.62 Phantom Sound Suppressor to work with not only with 7.62×51 (.308 Win) but also .300WinMag (yes, the Phantom is guaranteed for use on the 300 WinMag), 7.62×39, and 5.56/.223 to name a few calibers. Basically, if the bullet diameter is .30caliber or less the 7.62 Phantom can be used. Of course verify with YHM if any “exotic” calibers or applications are being contemplated. The limiting factor is getting the Phantom Flash Hider adapted to your barrel. The Phantom suppressor is even usable on AK Krinkov style weapons, chambered in 7.62×39 or 5.45×39, once a custom machined adaptor fitting the Krink’s 24mm threads is fashioned. The 7.62 Phantom is designed to reduce muzzle noise up to -32db. The Phantom 7.62 does sacrifice -3db rating compared to YHM own suppressor specifically designed for .22 calibers. This is a result of the increased diameter of the .30 caliber hole versus a .22 caliber hole losing some sound suppression efficiency.

The Phantom 7.62 suppressor was mounted and tested on a variety of weapon platforms consisting of a Rock River AR-15 chambered in 5.56, Century Arms M72 AK chambered in 7.62×39, Armalite AR-10A4 chambered in 7.62×51(.308 Win), and finally a Weatherby Custom TRR rifle chambered in .300 WinMag. It was as simple as installing a Phantom flash hider on each weapon. Conveniently, each rifle had a barrel with a pre-existing thread pitch that accommodated the Phantom flash hider. The ARs and AK have the Phantom flash hider left on permanently. The Phantom flash hider is not only an ingenious mounting system for the suppressor body, but also an effective flash hider in it own right. The Phantom flash hider is added to the .300 WinMag rifle in lieu of the attached muzzle brake when the suppressor is to be used. The brake is missed too much in terms of recoil management to leave the Phantom flash hider on full time.

Conversations with YHM’s Steve Dwight indicated that most users of their sound suppressors do not use subsonic ammunition in conjunction with the Phantom Sound Suppressor. The loss in terms of ballistic capability combined with the cost of specialized sub-sonic rifle ammunition and difficulty of finding quality subsonic ammunition being the root reasons. Many users feel the Phantom’s ability to minimize muzzle blast is well worth using it even though the prominent sonic crack is still present when using standard supersonic ammunition.

The Yankee Hill Phantom 7.62 suppressor was tested over an extended period of time consisting of numerous range visits. The advantage of the YHM QD method became quickly apparent and appreciated as the Phantom suppressor was shifted between the different rifles. Individual weapon’s point of impact (POI) did shift when the suppressor was installed. This is to be expected whenever hanging something off the end of a rifle barrel. It changes the barrels harmonics. What was closely monitored was if the point of impact stayed consistent once logged in for when the suppressor was installed on a specific rifle. Another important consideration for a suppressor is if the accuracy of a rifle is impacted negatively. This is important if long range work is considered with standard supersonic ammunition. Standard loads used were Federal Match 168gr for the AR-10A4 7.62×51/.308 Win, Black Hills Ammunition 55gr FMJ and 69gr Match for the 5.56 Rock River AR-15, 190gr Match for the Weatherby .300 WinMag, and Wolf Military Classic 124gr FMJ for the Century Arms M72 AK. Every rifle’s point of impact behaved directionally different when the Phantom suppressor was installed, but stayed consistent between the removing and re-installing the Phantom suppressor. POI shifted no more than a couple of inches left/right and up/down. Group sizes generally stayed equal or increased only slightly when compared to groups fired without the suppressor installed.

Engel Ballistic Research (EBR) is a primary source of quality subsonic ammunition due to the variety of calibers and loadings offered. Another reliable source for .308 Win subsonic loads is Corbon. Engel Ballistic Research’s (EBR) 5.56 NATO/.223 Ultra Stealth Match Subsonic (63gr Sierra Match bullet), 7.62NATO/.308 Thumper Subsonic (180gr bullet), .300 WinMag Subsonic (220gr bullet), and 7.62×39 Jackhammer Subsonic (220gr bullet) loads were tested. None of the EBR loads use fillers and all are loaded with accuracy in mind. The 5.56/.223 Ultra Stealth is designed intentionally not to cycle the rifle’s action for the maximum efficiency in terms of sound reduction and performs well in ballistic gelatin tests tumbling within 2-3 inches of penetration. Readers will find that subsonic loads do not typically cycle in an automatic rifle. This is not a great hindrance as an AR rifle with a tactical latch is almost as quick to cycle manually as a bolt action. The 7.62NATO/.308 and .300 WinMag loads are created from match grade components for ultimate accuracy. The 7.62×39 Jackhammer load is unique in the industry in that it is designed to cycle in M16 platforms with or without a suppressor mounted in both semi-and full automatic modes. EBR reports AK weapon platforms can be made to work with the Jackhammer after slight re-working of the feed ramp. The light recoil of the subsonic Jackhammer load makes it extremely controllable in full automatic mode.

Subsonic rifle ammunition is a different creature ballistically compared to standard loads confined to not much more than 150 yards distance for accurate shooting due to external and terminal ballistic reasons. It was determined that either a detailed log had to be kept for scope adjustment or scope reticle hold-over point written down when going from supersonic ammunition to the more specialized subsonic rounds. The subsonic loads dropped approximately 16-20 inches when fired at 100 yard targets compared to 100 yard zeros with the standard velocity loads. Windage adjustments were also necessary measuring anywhere from 4 to 8 inches left or right depending on the rifle. A user will definitely have to familiarize oneself with these range behaviors with different weapons and keep detailed records if contemplating switching back and forth between standard loads and subsonic loads. Several range visits would be prudent in confirming these findings.

The range experience was rather subjective in evaluating the YHM Phantom suppressor’s raison d’être – ability to lessen or dampen noise. No high tech auditory monitoring gear was used testing the Yankee Hill Machine Phantom 7.62 suppressor; just expectations based on previous experiences along with suppressors from other manufacturers on hand for direct comparison with ammunition from the same lot umber being fired out of multiple suppressors. The more one studies suppressors as a subject matter the more one realizes even with the audio equipment there are many variables in getting an accurate db reduction reading: i.e. atmospheric conditions, installation method of the suppressor, type of weapon used, first round pop phenomenon (FRP), etc. EBR’s website is an informative place to start searching into the facts of sound suppressors’ capabilities in combination with subsonic ammunition.

It is quite interesting to be sitting or lying behind a berm as rounds pass overhead. This was done to both get an idea of how effective the YHM Phantom was in reducing the sound of a round fired and masking the location of the shot. While this may strike many as unsafe or irresponsible, it was managed as closely as possible to ensure safety. It was no different than working the target pits at a rifle competition. The supersonic rounds were clearly audible, but the Phantom’s ability to mask the normal muzzle blast signature made identifying where the shot came from more problematic. This is further enhanced the farther away the shooter is from the target. The EBR subsonic rounds were very impressive in this range test format. The sound of a round striking a steel target near your position with no prior warning is eerily impressive. This was the case when the shooter is 100 yards away firing over your head at a target beyond you. This minimal firing signature resulted from combining the YHM Phantom suppressor and EBR ammunition. The Phantom suppressor was also analyzed when standing next to a weapon firing. The use of hearing protection was not needed, especially with subsonic ammunition. The Yankee Hill 7.62 Phantom held its own in direct comparison with other sound suppressors during the entire evaluation; many of which cost significantly more than the Phantom. The YHM Phantom 7.62 Sound Suppressor succeeds in achieving adaptability while remaining effective as a suppressor.

Yankee Hill Machine Company, Inc
20 Ladd Ave, Suite 1
Florence, MA 01062
(413) 586-1326
www.yankeehillmachine.com

Engel Ballistic Research, Inc
(512) 360-5327
www.ebr-inc.net

Sound Technology
PO Box 39
Pelham, AL 35124
(205) 664-5860
www.soundtechsilencers.com