Unless it is specially modified, this ammunition will fail to cycle a semi-automatic firearm.

Pick any 5.56x45 cartridge at random. Odds are its muzzle velocity is supersonic. Even a heavyweight 77 grain load is usually loaded to a muzzle velocity of around 2,720 fps, which is well over double the speed of sound.

That makes this round by Armscor truly special. Its muzzle velocity is a cool, subsonic 1,100 fps (in conjunction with a 18” barrel), which makes it of obvious utility to a suppressed rifle. Its report does not include any noise that a suppressor isn’t designed to dial down! You’ll hear the difference, for sure.

Subsonic 5.56x45 does come with drawbacks. Hornady’s extremely high-quality open tip match is reasonably accurate within 100 yards, although it isn’t of much use beyond that range. It also can’t deliver terminal expansion, which, alongside its extraordinarily light striking energy, makes it totally inadequate for hunting medium game.

20 Round Box

Features and Specifications:
Manufacturer Number: F AC55677SS-200
Caliber: 5.56 NATO
Bullet Weight: 77 Grains
Bullet Type: Open Tip Match
Muzzle Velocity: 1100 fps
Muzzle Energy: 207 ft/lbs
Reloadable Brass Case
20 Rounds