Subsonic Striker: Introducing a New Frangible Subsonic .223 from Allegiance Ammunition

By Todd Burgreen

Suppressor use amongst the military, law enforcement and civilians has never been so popular. The benefits of suppressors are hard to dispute, and suppressor manufacturers are expanding production to unimaginable levels. A company contributing to the suppressor marketplace from a different angle is Allegiance Ammunition with its SilentStrike™ ammunition. SilentStrike is notable for its fully functioning frangible subsonic .223 product line-up designed to work with AR15/M4 platforms. There are currently three loads available: 110-grain, 97-grain and 80-grain. Each load offers its own unique performance characteristics.

It does not take a drastic leap of imagination to visualize what roles fully functioning AR-compatible subsonic Allegiance Ammunition would fill. Anything from sentry removal—canine or other—to indoor CQB operations comes to mind. Allegiance’s own literature points out the advantages of such ammunition to, for example, a law enforcement or military team needing to operate covertly while moving through an objective. SilentStrike’s velocity of 975 feet per second eliminates the supersonic crack of the round moving downrange. A quality suppressor eliminates the muzzle signature. The SilentStrike line is not merely about subsonic performance; its unique bullets include such features as frangible tungsten powder cores, which are devastating against soft tissue even at subsonic velocities.

A SIG SAUER SIG516 Patrol AR rifle and SIG SAUER SRD556-QD suppressor were used while evaluating Allegiance Ammunition’s offering. The SRD556-QD weighs 14 ounces, is 6.5 inches long, 1.625 inches wide and offers a sound rating of 134db with supersonic ammunition. SilentStrike requires no modification to the weapon to perform reliably. A standard H-buffer, stock recoil spring and minimum .065–.070 gas port are base requirements that most factory ARs satisfy. A 1:7 barrel twist rate is preferred to stabilize the SilentStrike rounds.

Conversation with Allegiance Ammunition’s Jeff Mullins leaves no doubt about the in-depth product development that takes place with each product. Allegiance is constantly approached by various agencies/units and special operations units to create custom ammunition for specific mission parameters. Not only is a fully functioning subsonic load a challenge; the need to have effective terminal ballistics only compounds the problem. This is one reason why frangible bullet design was turned to. The tungsten powder not only allowed for heavier bullet weight—after all, subsonic loads are restricted to traveling at no more than (Approximately) 1000 feet per second so the heavier the better for ballistic effect—but also allowed for a round to basically unload/explode in the target for serious terminal effect. Typical standard copper-jacketed loads traveling at less than 1000 feet per second do not come close to the performance. The Allegiance frangible round creates a wider circumference of damage than traditional bullets, producing a larger permanent wound channel than a typical .223 round. Frangible ammunition also offers beneficial characteristics when fired indoors, reducing concerns about either ricochet or penetrating a target and injuring anyone/anything beyond it.

The .223Rem 110-grain subsonic load was the first subsonic frangible load created by Allegiance. The focus with the 110-grain SilentStrike was introducing the heaviest bullet within the overall length operating parameters of the M4 rifle. A frangible tungsten powder based bullet was finally settled on. This was a two-year process. Barrel length, gas port and twist rate were just a few of the factors needing consideration once the bullet profile, weight and make-up were decided upon. The 110-grain SilentStrike load will function in 7-inch, 14-inch and 16-inch barrels with 1:7 twist.

Allegiance Ammunition expanded its .223Rem SilentStrike offerings with the 97-grain SSL load. This load is more typical, being jacketed and non-frangible. It offers subsonic functioning at a more economical price point. The 80-grain SilentStrike .223Rem load was created due to a request for a load more appropriate for CQB.

Jeff Mullins describes scenarios where the top 10 or 15 rounds in an AR magazine are SilentStrike loads for any initial contact before resorting to standard ammunition. Frangible bullets are most associated with target practice on steel, often at close range. Frangible bullets also have a specialty role in certain tactical situations, where any chance of over-penetration cannot be tolerated. Allegiance Ammunition has taken this a step further with its SilentStrike product line by utilizing frangible bullets in functioning subsonic loadings.


Allegiance Ammunition

This article first appeared in Small Arms Review V21N7 (September 2017)
and was posted online on July 21, 2017


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