May 15th, 2018 by asjstaff

With no prior military service and an affinity for wing shooting, it took a while for USGI builds to reach the top of my list. In fact, I was planning to build a new snow goose shotgun when the opportunity to start on an A2 build landed in my lap. Of course, I couldn’t pass it up. And, honestly, after a slew of higher-end builds, it was probably about time to touch base with the basics.

After researching my options, I determined Fulton Armory was the best choice for upper receiver parts due to the overwhelming expertise within their organization, availability of good quality parts and their compatibility, and reputation for customer service. Plus, their prices are competitive, especially for stripped receivers and parts kits.

If you so choose, a small bump in price will also net you a fully-assembled FAR-15 upper receiver. I opted for the stripped upper receiver and parts kits to aid with testing and evaluation of The Device MK I Mod 0, and also because I get satisfaction in successfully building my firearms.

Now, The Device (above) is an animal all its own. Technically, it’s a tool; a beastly hunk of milled aluminum that’s designed to secure upper receivers. Specifically, it provides the most usefulness with assembly and maintenance of A2-style upper receivers. And for this A2 upper it worked perfectly, although it wasn’t needed for many steps in the assembly process.

Fulton Armory also won me over a bit with their availability of firearms guides, including The AR-15 Complete Assembly Guide by Walt Kuleck and Clint McKee (see my review here). I found it to be a great resource and I recommend it for all owners of AR-15 platform weapons.

Plus, each copy is autographed, which is a neat way to for the authors to show pride in their work.

But back to the hardware…

The Fulton Armory stripped M16A2 USGI upper receiver I received was nearly flawless. The Type III Hard Coat Anodized finish is as good as it gets – consistent and smooth. I found one near-microscopic nick in the finish that barely made it into the 7075 T6 aluminum; most likely somehow my own doing since Fulton packaged the upper and parts adequately for shipping.

Both the forward assist and rear sight roll pin holes are nicely beveled on the installation sides, as well as the pivot and takedown pin holes in the lugs.

The square forging mark on the left side of the upper receiver is indicative of the Brass Aluminum Forging Enterprises’ work, a USGI Contractor with much experience and a solid reputation for forgings.

The barrel nut threads were cleanly-cut, sharp, and free of any rogue material or finish. Inside, the receiver is seemingly polished to perfection.

Areas for the rear sight, forward assist, and ejection port cover were all cleanly created and finished and looked great.

And finally, the iconic carrying handle, smooth and sturdy, easily met expectations.

The upper receiver is available with M4 feed ramps, but because of the route I plan to take this build I opted out, as seen above.

Fulton’s A2 Upper Receiver Parts Kit is essentially their A2 Rear Sight Complete Kit and Upper Receiver Parts Kit combined, and includes all parts needed to complete an A2 upper receiver assembly.

In addition, buying the complete Upper Receiver Parts Kit will save you $24.95 when compared to buying the Rear Sight Kit and Upper Receiver Parts Kit separately.

At the workbench, I first sorted and hand-fit all parts, checking for proper fit to the upper receiver. A surrogate charging handle, bolt, barrel, and barrel nut were tested in the upper receiver. Internal dimensions were also tested with The Device’s surrogate BCG/charging handle.

Finally the upper receiver was mated with several lower receivers. Everything fit very well and the stripped upper was locked into The Device to begin assembly.

The dust cover went on without a hitch. It fit perfectly to the upper receiver and testing with The Device’s surrogate BCG found it to be mechanically sound, delivering the resounding and satisfying “Snap!” we all expect.

Installation of the forward assist proved a straight-forward task. The deep and wide bevel on the installation side of the forward assist roll pin hole made driving the roll pin painless.

The forward assist assembly moved freely within the forward assist boss and testing with a surrogate BCG and charging handle confirmed the pawl’s positive contact and correct functionality.

The rear sight base and elevation indexing knob also found their homes with relative ease. The elevation indexing knob is particularly well-made, fit perfectly, and functioned with impressive smoothness. A standard amount of play existed between rear sight base and upper receiver.

Surprisingly, installing the rear aperture was the trickiest part of the assembly. But only because Fulton includes a very good rear aperture leaf spring that exhibits substantial force on the aperture.

A quick final roll pin through the windage knob followed by a function check of the rear sight and I was in business! As with the elevation knob, the windage knob functions very well, delivering precise adjustments and solid lock-up with zero slop.

Fulton Armory’s A2 USGI Upper Receiver and A2 Upper Receiver Parts Kit were easy to assemble every step of the way. I didn’t find myself fighting any part of the assembly; it all came together as expected.

All moving parts – ejection port cover, forward assist, and rear sight – performed their duties without issue and look great. I expect this now complete upper receiver to fare quite well as part of my FAR-15 rifle build.

There is an incredible amount of knowledge and experience within Fulton Armory and their guidance and selection of components most certainly did not disappoint for this USGI A2 upper receiver build. All components are top-notch Mil-spec components; well-finished with near-perfect fit.

Of course, this is just the beginning of this rifle build. The completed upper has yet to be field-tested. If I run into issues I will report back, but I have no reason to believe this complete upper will not perform exceptionally well once it becomes a completed rifle upper. As evidenced through this USGI A2 upper receiver build, Fulton Armory is a top-notch resource for U.S. gas-operated service rifle components and advice.

Specifications: Fulton Armory A2 USGI Stripped Upper Receiver

Price as reviewed (A2 – no feed ramps): $99.95

Overall: * * * * *
Fulton Armory’s stripped A2 USGI upper receiver is a precisely made, rock solid, well-finished Mil-spec upper receiver. Featuring beveled pin holes, sharp barrel nut threads, a great carrying handle, and flawless Type III hard coat anodize finish, Fulton’s A2 upper receiver is an excellent choice you won’t want to skip over for your next build.

Specifications: Fulton Armory A2 Upper Receiver Parts Kit

Price as reviewed: $69.95

Overall: * * * * *
A complete kit consisting of all new, very clean parts, Fulton Armory’s A2 Upper Receiver Parts Kit pairs beautifully with any stripped Mil-spec A2 upper receiver.

Posted in Product Reviews, Rifles Tagged with: , , , , , , , , , , , , , , , ,

August 6th, 2016 by asjstaff

The AR57 Is An Excellent High-capacity Yet Affordable Alternative For Self-defense, Varmint Hunting

The AR57 (also known as the AR Five Seven) upper receiver for the AR-15 has two claims to fame: a 50-shot capacity and downward ejection for ambidextrous operation. Operating by simple blowback, this upper is available in 6-inch pistol and 16-inch rifle versions, with the latter being reviewed here.

Manufactured by the eponymous AR57 LLC, and chambered in 5.7x28mm, this upper is less powerful than the standard 5.56mm version, but it has certain tangible advantages, including reduced muzzle blast, a high practical rate of fire, nonexistent recoil, and the ability to use folding stocks. Since the buffer is located within the receiver, folding stocks may also be used for compact storage or carry.

To load, place the baseplate of a standard FN P90 magazine into the recess on the front of the upper, then press the feed lip side down on the catch located above and slightly back of the bolt. To charge, pull on the right-side nonreciprocating handle and release. The right-side charging hand placement makes it accessible for operation by the strong hand. Since it only has to be operated once every 50 shots, the time penalty for moving the hand off the pistol grip isn’t too great.

Empties will eject downward through the nominal magazine well. Some people use a 20-round magazine body with the feed lips, spring and follower removed to act as a brass catcher.

The magazine has no provision for activating the bolt lock when empty, but the bolt can be locked open using the catch on the lower. The upper runs very cleanly and reliably, requiring no maintenance after the first 500 shots.

The AR57 comes with a medium fluted barrel, reasonable for a varmint rifle but excessive for a defensive carbine. Burning around six grains per shot, 5.7x28mm runs much cooler than 5.56mm, which burns four or more times as much. That yields much reduced muzzle blast and far greater heat endurance, of course at the cost of a roughly 40 percent slower bullet.

The baseplate of a standard FN P90 magazine fits snugly into the recess on the front of the upper.


The adequacy of 5.7x28mm for stopping human aggressors has been in dispute ever since its introduction. Some of the lighter bullets available for the caliber have traditionally been tipped or leadless hollow points prone to excessive fragmentation. Firing a 27-grain lead-free hollow point at a full, upright 12-ounce beverage can did not produce a complete penetration – an excellent result for a range or a small varmint round, but not a man-stopper.

With no protruding magazine, the AR57 allows shooters to get very low into a prone position.

Expanding ammunition with better penetration is also available from FN, along with nonfragmenting 40-grain FMJ American Eagle. Recently, RR Weapon Systems introduced two 37-grain all-copper loads, 37F (fragmenting) and 37X (expanding). In testing 37X, I found it much hotter than the alternatives and a very reliable terminal performer. The three-petal bullets expanded to fill 2/3-inch circumference and penetrated around 12 inches into gel. Velocity was around 2,680 feet per second with a standard deviation of under 10, so it was no surprise that it produced groups a touch under 2 inches. Other than handloads with 40-grain Vmax, all other ammunition grouped closer to 2.5 to 3 minutes of angle when fired using a 2.5x scope.

The AR57 is an excellent choice for self-defense, especially for individuals of smaller stature.

The main limitation on the use of an AR57 for varmint control is the space available for optics. Because the magazine is lifted up for unloading, the potential length of the scope is sharply limited. I have been able to fit 2.5x or 4x prismatic scopes, but anything longer caused interference. Considering these sighting limitations, I would rate it as suitable for small rodents out to 100 yards.

Accuracy is a less important consideration for defensive use. Follow-up shots with the AR57 are limited only by the trigger finger dexterity, as it showed no muzzle rise at all. Up close, this platform would be better served with a red dot sight and a laser for rapid aiming. I’d like to see a defensive variant with a pencil-thin barrel and a more skeletonized forend developed alongside the current version.

Compared to the PS90, the AR57 is the heavier option, even when polymer lowers are used. It is also longer. But the advantages of an AR57 are numerous. Even a stock AR-15 has a better trigger than a PS90, and aftermarket options can enhance that difference a great deal. AR lowers allow adjustable length of pull, and AR ergonomics make more use of existing training, other than in the reloading process. The height of sights over bore is significantly less, making accurate hits easier.

This functional upper features several advantages, including reduced muzzle blast, a high practical rate of fire, and nonexistent recoil.

Compared to a 5.56 upper, the AR57 is simpler to clean, generates less felt recoil and much less muzzle blast. With no protruding magazine, it allows the shooter to get very low into a prone position. Two full 50-round P90 magazines weigh as little as one 5.56 30-rounder, so you can carry a lot of ammunition.

At $745 direct from the manufacturer or an authorized dealer, it is less expensive than a PS90 carbine (which lists at $1350), even after the cost of an AR-15 lower is added in. The 5.7x28mm ammunition costs about the same as 5.56x45mm, though the variety of available loads is definitely smaller.

The niche I see for AR57 – besides it being plain fun to shoot – is for self-defense by the same slightly built individuals who would have picked an M1 carbine in the past. It requires less upper body strength to use than most long guns, and gives 50 shots without reloading. A small teenager or a fragile senior can run it with ease, but the rest of us won’t need an excuse to enjoy using this upper. ASJ


Editor’s note: For more information about the AR57, visit

Posted in Long Guns Tagged with: , , , , ,