What is .300 Blackout?
.300 AAC Blackout (300 BLK) is a .30-caliber cartridge built on a trimmed 5.56 NATO case, so it runs in a standard AR-15 with nothing more than a barrel swap — same bolt, same magazines. It was designed to deliver .30-caliber punch from short barrels and to run exceptionally well suppressed, across both subsonic and supersonic loads.
Subsonic vs. supersonic .300 Blackout
- Subsonic (typically 190–220gr): Stays below the sound barrier for the quietest suppressed shooting. Ideal for home-range plinking, pest control, and close-range hunting.
- Supersonic (typically 110–150gr): Flatter shooting with more energy downrange — the better choice for hunting and general-purpose use out to a few hundred yards.
What is .300 Blackout good for?
300 BLK excels in short-barreled rifles and pistols, suppressed setups, hog and deer hunting at moderate range, and home-defense carbines where a compact, controllable package matters. It delivers far more bullet weight than 5.56 from the same platform.
.300 Blackout vs. 5.56 NATO
5.56 is lighter, faster, and flatter at distance. .300 Blackout trades long-range velocity for heavier bullets, better short-barrel efficiency, and dramatically better subsonic/suppressed performance. Many shooters keep both uppers on one lower.
Will .300 Blackout work in my AR-15?
Yes — you only need a .300 Blackout barrel. It uses the same 5.56 bolt and STANAG magazines. Important safety note: never load .300 Blackout into a 5.56 chamber; always keep the ammunition clearly separated.
Shop .300 Blackout
Browse our .300 Blackout ammunition, including subsonic loads and bulk 300 Blackout buckets.
.300 Blackout FAQ
Is .300 Blackout good for hunting? Yes — supersonic loads handle hogs and deer well at moderate range.
Do I need a special lower or magazine? No. Only a .300 Blackout barrel; the bolt and magazines are standard AR-15.
What is the best .300 Blackout for suppressed shooting? Heavy subsonic loads (190–220gr) are purpose-built for quiet, suppressed use.