Shrike's 5.56mm AWS

By Jeff W. Zimba

For several years there have been underground rumblings concerning something called “The Shrike” that was going to change the way we look at and utilize the M16 series. That day has finally arrived. Manufactured by Ares Defense Systems, it is poised to hit the market in late February and it has been one of the most anticipated weapons systems in recent memory.

The Shrike 5.56™ is a “drop on” belt-feed upper receiver assembly for the AR-15/M16 family of firearms. It requires absolutely no permanent modification to the lower receiver and allows the shooter the option of belt feed operation while still allowing the alternate use of the standard M16 detachable box-type magazine at the operator’s discretion. This new upper receiver assembly is an accessory and not a firearm in and of itself.

The namesake of this revolutionary new unit is oddly enough, a bird. The Northern Shrike (Lanius excubitor), native to Canada is sometimes referred to as the butcherbird because of its practice of impaling its prey on thorns and barbed wire similar to the way butcher hangs meat in their shops. It is a small creature that packs an enormous amount of power, which also seems to describe this new weapons system perfectly.

The Shrike was invented and designed by Geoffrey A. Herring of Ares Defense Systems in Blackburg, Virginia. Herring has several patents pending on the Shrike. It was originally conceived by Herring as a way to provide the rifle squad with a Squad Automatic Weapon (SAW) without subtracting a rifleman. In order to meet this MENS (Mission Essential Need Statement) strict design parameters were required.

The weight was a major concern and with the complete rifle in the M4 configuration, including the Shrike unit, weighing in at less than 8 pounds, empty, Herring was well under the average 15-27-pound guns that troops were currently fielding.

As the M16 has been our primary service weapon for over 40 years, as well as that of many of our major allies, it seemed to be a natural choice as the host firearm for the Shrike. There were several attractive aspects to this, i.e., a substantial number of trained service personal already familiar with the M16 lower receiver, as well as a large national inventory already of spare parts necessary for the lower half of the firearm. This presented a cost-effective concept for the potential users.

The Shrike, well suited for military and law enforcement applications, was also designed to be a user-friendly system for civilian shooters and class III enthusiasts also. The system was developed with the idea that it must be able to function in a semiautomatic-only variation that would be adaptable to the thousands of AR-15 rifles in private hands. This brings a whole new dimension of shooting to those who do not live in class III friendly states, have trouble with their “Cleo’s” signing off on BATF Form 4s or just don’t want to spend the money or engage in the hassle of lengthy paperwork required to buy a registered machine gun.

Recreational and competitive shooters will love the option to use belts rather than standard box magazines for several reasons. Box magazines are easily damaged, cumbersome while trying to shoot from the prone position and they are becoming more expensive every day. The M27 links used with the Shrike are currently inexpensive and plentiful and when the box magazine is not inserted, the weapon can be much lower to the ground or shooting bench. For those who have purchased their AR-15 since 1994 and have guns considered to be “post-ban,” Ares Defense is offering a Shrike in a post-ban configuration.

Class III enthusiasts certainly have something to celebrate with the introduction of the Shrike. Since the 1986 ban on machine gun manufacture for civilian ownership has gone into effect, prices on transferable guns have gone through the roof. There were very few belt-fed machine guns chambered in 5.56x45mm NATO prior to the ban and prices on the ones that were available have become out of reach for most collectors. Before the introduction of the Shrike the only options were to spend in excess of $40,000 on a transferable Stoner 63(A) when one was available, or if you were fortunate enough to have a Class III license you could have purchased a “Pre-86” dealers sample FN Minimi in the area of $60,000 - $70,000 or more. Now we have the option of purchasing an M16 in the area of $6,000, adding a Shrike for another $2,995 and having a 5.56x45mm NATO belt-fed machine gun for well under $10,000.

The Shrike functions with either readily available M27 ammunition links or with the standard M16 box magazine currently on the market. Unlike the Stoner 63 there is no need to rearrange any parts when swapping from one feed type to the other. You can fire a magazine and empty it, lift the top cover and drop a belt into the feed tray, hit the bolt release to chamber a round and fire the belt until it is gone. Once the belt is gone you can insert another box magazine into the magazine-well, charge the firearm and continue firing.

The receiver of the Shrike is manufactured from 7075-T6 forgings. The quick-change barrel includes a barrel extension with non-adjustable headspace. It is gas-piston-operated and the standard handguard is insulated with a sheet-metal heat shield. Most of the parts are proprietary. Early prototypes used M16 bolts but Ares found that manufacturing their own parts, with their own modified design specifications results in a better end product. As it stands now, the only part that is unmodified from a standard M16 upper receiver assembly is the firing pin.

The lower receiver remains unmodified with the exception of adding a stronger main spring to assist in stripping rounds from the links, which require a higher stripping force than from a standard box magazine. The bolt catch supplied with the Shrike is also different, as the top section is displaced slightly rearward to bring it out from behind the feed tray. This part exchange takes less than three minutes and does not affect the way your lower receiver operates with any standard upper receiver.

Most weapons share several functions with existing weapons and the Shrike is no exception. Early pioneers in the art of gun design such as John Browning, Sir Hiram Maxim and Melvin Johnson developed principals that continue to be utilized and improved upon and new designers employ these principals along with new ideas to achieve their products. The Shrike uses a two-step shuttle feed with a traditional top cover such as the MG42. The quick-change barrel system is similar to that of the Stoner 63(A). Unique features not found in other weapons systems include mating of the Shrike to the factory lower receiver exactly like the original upper receiver and providing the option of using belts or magazines without modifying the lower receiver.

The fire control is exactly the same as your standard AR-15 or M16 and is not changed in any way by the addition of the Shrike upper receiver. If you have a semiautomatic-only AR-15, it will function in “SAFE-SEMI” just like the original. Since the bottom of Shrike bolt carrier was designed to provide the same functions as the original bolt carrier in the factory upper receiver, if you purchase the semiautomatic-only version, it will function with a registered lightning link. If you have burst fire control components in your lower receiver you will achieve the same performance with the Shrike upper as you do with the factory upper receiver, thus providing a closed-bolt “SAFE-SEMI-BURST” function. If you have a four-position trigger mechanism you will still be provided with a closed-bolt “SAFE-SEMI-BURST-FULL” function. If you have an open-bolt fire control mechanism such as the unit designed by Henry Tatro of Colt Industries, you will have an open-bolt “SAFE-FULL” mechanism such as the one used in the Colt M16A2 LMG, Model 750. A standard M16 type Shrike bolt carrier will have to be modified to work in this system and Ares Defense may provide this service to their customers at some point in the future.

The TAC™ trigger system invented by Terry Soper produces a closed-bolt “SAFE-SEMI-SEMI/AUTO” function very similar to the Steyr AUG rifle. When the “AUTO” position is selected the operator can fire in either “SEMI” or “FULL” depending upon the amount of force applied to the trigger. All of the above trigger mechanisms will function and may be used with Shrike as described.

Ares Defense has designed a few of their own trigger systems to work with their upper receiver to permit open-bolt fire in the “FULL” position when installed in a registered lower receiver. Because the Bureau of Alcohol, Tobacco and Firearms (BATF) has ruled that an open-bolt firing mechanism installed in a semiautomatic-only firearm manufactured after 1981 would be a machine gun in and of itself, they designed these only to fit registered MIL-spec lower receivers. The first variation produces an open-bolt “SAFE-AUTO” function. The second variation produces a closed-bolt “SAFE-SEMI” and an open-bolt “AUTO” function. These will both be available as accessory options for those with approved Form 4’s or an FFL/SOT.

When I inquired as to what configurations the Shrike would be offered in, Geoff smiled and quoted Henry Ford’s famous “You can have any color Ford that you want, but they will all leave the factory black.” He said that in order to keep cost to a minimum for the end users they have settled on one basic configuration that should fit the majority of applications. A standard unit will be shipped with a 16-inch non-chrome-lined quick-change barrel with a twist rate of one turn in 9 inches. It will have a nylon-insulated hand guard, fixed sights, and a MIL-STD-1913 rail on the top cover, and a 1/4-inch small front take down pin. An offset pin can be used to mate it to the large-hole Colt AR-15s. Purchasers will have the option of a full-auto or semiautomatic-only bolt carrier and a pre-ban or post-ban barrel. The only difference between the full-auto and the semiautomatic-only is the stripped bolt carrier. The post-ban barrel has no threads and employs a permanently attached muzzle brake as per BATF guidelines and the pre-ban barrel has a standard 1/2x28 thread with a flash hider.

There are several accessories that will be available for the Shrike. Some are shorter barrels (13 - 20 inches), bipods, tactical barrel bags, SAW belt-box adapters, tripod T&E adapters, folding sights, a belt-linking machine and more. Proof of approved Form 4 or FFL/SOT must accompany any order for barrels shorter than 16 inches or for any open-bolt fire control components.

Just like any firearm, barrel life is going to depend heavily on maintenance and type of usage. If the operator practices good fire control discipline and regularly maintains the system the barrel should meet or exceed 20,000 rounds. If the shooter fires in 200-round bursts, reloads and does it over and over, (like we often see at large recreational events) barrel life will be significantly shorter.

Offering the Shrike in other calibers is not something on the horizon at this time. Many people have expressed interest in a 7.62x39mm caliber but it doesn’t seem practical now. The only belts that are really available for this caliber are Soviet RPD belts and Czech VZ-52 belts, both being fairly rare and somewhat expensive. The fact that they are both of a non-disintegrating design will further hinder performance of the Shrike due to the link ejection port being positioned above the brass ejection port. Just like there is an exception to every rule, there may be potential for one more caliber though. Where some countries do not allow civilian ownership of firearms in calibers slated for military use, the 5.56x45mm NATO may be restricted in some areas. If there were enough demand, Ares Defense would not rule out a conversion for .222 Remington that could be accomplished with a simple barrel change.

Shooting the Shrike

The configuration we brought to the range was a pre-production model with a 14-inch barrel in M4 configuration. We opted to use an optional vertical pistol grip on the front handguard. Before we started shooting we all had a briefing on the Shrike System and it was explained that we were shooting the last experimental, pre-production model manufactured before final production was implemented. Herring made us aware of upgrades implemented between manufacturing this model and the production model that would be shipped very soon. The level of research and development that had gone into this project over the last few years was now becoming obvious, as no detail seemed to be left to chance.

As we began the testing, Herring demonstrated the ability of the lower receiver, now with the Shrike upgrade of the new spring and bolt catch installed, to operate flawlessly with a M4A1 “standard issue” upper receiver as used by USSOCOM forces. He inserted a 30-round magazine and emptied it immediately. After the magazine was empty the bolt was locked open by the magazine follower such as in any standard AR15/M16. Now it was time to get to the Shrike.

The first of our tasks was to test the Shrike for belt pull. Many people who are not familiar with a belt feed mechanism are not aware of the amount of energy necessary to operate the action. It takes much more energy to strip a round from a belt than it does to strip a round from a conventional box magazine. In a box magazine the rounds are usually under spring tension being forced in the direction of the action and will automatically advance as each round is fired. In a Belt feed mechanism the action of the firearm must actually pull the belt into the mechanism and this requires additional energy. When you add the additional weight of an extremely long and heavy belt the extra energy necessary required to run the action is compounded.

Herring was first to shoot the Shrike in this testing phase and had actually been shooting 100-round hanging belts since this project was in its early stages. This was something he did on a regular basis and once again this task was accomplished with ease. After a brief conversation he loaded a hanging 200-round belt from the Shrike and held it over his head to try and keep the belt from hitting on the ground. A few rounds were fired in “SEMI” and then he switched the selector to “AUTO” and emptied the remainder of the belt without a malfunction. Everyone was satisfied with these results as it was an extreme situation because the belt is usually only pulled from a very short distance, most typically a hanging ammo box that is mounted immediately below the receiver. Since we were conducting a test we decided to push on. A belt over 300 rounds was linked and Herring had to stand on the tailgate of one of our test vehicles and hold the gun high over his head again to get as many rounds in the air as possible. At this point there was over 10 feet of linked 5.56x45mm NATO ammunition hanging from the feed tray of the Shrike. He again fired a couple of rounds on “SEMI” and switched the selector to “FULL.” After firing approximately thirty to forty rounds feeding flawlessly in “FULL,” he switched it back to “SAFE” and jumped down off the tailgate. Everyone in attendance decided that if this portion of the test were to go any further we would need an extremely long ladder. Our collective feeling was that it passed the belt pull test with flying colors and I even think it exceeded Herring’s own expectations.

The second phase of testing was to swap the feed device from one method of feed to another and back again without changing or altering the configuration, or even cleaning out remaining links from the link chute of the feed tray. We wanted to find out how it would function in a situation where a belt was expended and the availability of more ammo was only a standard 30-round box magazine. And then, going one step further, load with another belt.

A belt was loaded into the Shrike and it was charged. The entire belt was emptied and the bolt chugged forward. Upon this happening a loaded magazine was loaded into the factory magazine well and the charging handle was pulled back and dropped home. The entire 30 rounds were emptied in a few short bursts. With this, the magazine release was hit and the magazine fell to the ground. The top cover was lifted, another belt was inserted and with one hit of the bolt release, a round was stripped from the belt and locked into battery for firing. A few short bursts later and the last of the linked ammo was swallowed up by the Shrike. This test was also performed without failure.

Our next phase was to get the unit in the hands of several testers and get everyone’s individual opinion of comfort and controllability. All opted for a large belt and had different types of trigger discipline. Some fired several short bursts, some fired a small burst and a large burst and some just dumped their belts. Some of the shooters mentioned the presence of a slight “trigger-slap” and others felt nothing different than a standard M16 at all. The consensus of all the shooters, regardless of shooting style, was that the gun was very controllable and comfortable to shoot.

In absolute fairness, as the Shrike System definitely exceeded our expectations overall, the day was not without a few predictable slow-downs. As mentioned above, there were a couple of upgrades Herring implemented between this last pre-production model and those being manufactured for sale. One of these production upgrades consisted of changing the pin that secures the non-reciprocating charging handle to the bolt for cocking. On the early prototype the pin was simply pressed in and had a tendency to want to walk out. The production model has this pin cross-drilled and pinned to the charging handle to completely alleviate this problem. We experienced one slowdown due to this pin walking out as expected.

The second slowdown we experienced occurred when the pin that is part of the operating rod assembly sheared. Even with a problem of this magnitude, amazingly enough the system still continued to function firing in a three-shot burst mode. This problem has already been addressed as well in the series production phase by simply instituting an engineering change notice. All of our concerns were addressed and corrected prior to the first production run and we are now anxiously awaiting of the first shipment of the Shrike .556 Advanced Weapons System to arrive to their new owners.

Watch the pages of Small Arms Review for a future “Torture Test” and detailed photographic field strip and disassembly of the Shrike and information on new upgrades and accessories including the adaptation of the modified M203 40mm Grenade Launcher.

About Ares Defense Systems

Ares Defense Systems is an acronym for Advanced Research and Engineering Services for Defense Systems. Geoffrey A. Herring formed and licensed the company with BATF in 1997, in an effort to transform his passion for designing firearms and mechanisms into a business. Small arms study and metal machining have been cornerstones of Herring’s life since childhood.

Ares Defense Systems, LLC is primarily a Research & Development Laboratory with manufacturing capabilities. While some production components are sub-contracted to other establishments, the major portion of the products are machined in-house on MAZAK vertical and horizontal CNC machining centers. In addition to their own in-house projects, Ares Defense Systems, LLC provides small arms consultation and if needed, prototype development for companies with new and innovative small arms products.

Contact Information

Ares Defense Systems, LLC is located at the US Government’s secure Radford Army Ammunition Plant in Radford, Virginia, USA. Radford Arsenal is a restricted-access military reservation; therefore, all meetings are by appointment only.

Mailing Address
Ares Defense Systems, LLC
P.O. Box 10667
Blacksburg, Virginia 24062-0667 USA

Shipping Address
Ares Defense Systems, LLC
Radford Army Ammunition Plant
Building 208
State Route 114
Radford, Virginia 24141 USA

Telephone: (540) 639-8633
Fax: (540) 639-8634

Image Gallery

Shrike on display at SAR Show 2002 in Phoenix. Dan Shea Photo.

To remove the barrel, this lever is depressed with the thumb and the barrel can slide straight out and separate from the gas system as illustrated in this photo. Photos by Dan Shea.

To remove the barrel, this lever is depressed with the thumb and the barrel can slide straight out and separate from the gas system as illustrated in this photo. Photos by Dan Shea.

The link ejection port (A) and the brass ejection port (B). Photo by Dan Shea.

The feed tray on the left side of the Shrike. This particular unit is on a semi-auto Bushmaster lower receiver. Photo by Dan Shea.

The feed tray and top cover of the Shrike. It utilizes a two-step shuttle feed mechanism similar to the mechanism used in the MG42, MAG58 and M249. Photo by Dan Shea.

The Shrike can be fired using belted ammunition or fed from a conventional box magazine without changing the configuration of the rifle. From left to right: A belt is inserted in the feed tray, and the belt is fired and emptied. Upon finishing the belt a box magazine is inserted in the magazine well, the rifle is charged and the magazine is emptied. Photos by Jeff Zimba.

Photos from the “belt pull test”. 100-round hanging belts were used during regular firing. We tested the limits of the Shrike by trying 200-round and 300+ round belts and eventually ran out of height when we had the gun over 10 feet from the ground and it continued to feed it without difficultly. Photos by Jeff Zimba.