The .300 AAC Blackout, while occasionally seen in bolt rifles like Ruger’s American Rifle, is most commonly seen in AR-15 platforms. It’s essentially the same as the original .300 Whisper, but the Blackout includes a .015-inch longer throat. Identical loading dies are used for both. The Blackout allows for the creation of supersonic loads with bullets weighing 90 to 180 grains and subsonic (less than 1,125 fps) loads popular with suppressor owner with 200- to 230-grain bullets. The Blackout feeds from standard .223 Remington/5.56 NATO AR magazines, limiting overall loaded length (OAL) to 2.26 inches. Brass-trim specifications are 1.368 inches, with a trim to length of 1.358 inches.

The similar .300 Whisper, not Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) approved, was first created by J.D. Jones of SKK

Industries by resizing the .221 Remington Fireball to accept .308 bullets. The .300 Advanced Armament Corporation (AAC) Blackout resulted from a joint venture between AAC and Remington, the round SAAMI approved in 2011. The round delivers performance mirroring the Soviet 7.62x39mm.

You might ask, what is the .300 Blackout good for? Loaded with 110- to 180-grain bullets at supersonic velocities, the Blackout creates an effective hunting round for hog- to deer-sized game. Frangible 90- to 100-grain bullets make viable varmint ammunition. With 200-plus-grain bullets (requiring 1:8 to 1:7 rifling twist) subsonic loads many hog-control hunters prefer to help facilitate follow-up shots while addressing large

sounders are easily created.

Hog Killer

My Blackout experience, culling some 50 problem Texas hogs, involved a 10.5-inch barreled pistol and subsonic ammunition. This

experiment convinced me a Blackout/subsonic-ammunition combo isn’t ideal for such work. It will certainly kill hogs, but tracking is typically involved following double-lung hits. Head and neck shots are required if you wish to anchor them where they stand. Subsonic ammunition also required getting closer; kinetic energy delivery falling below 500 foot pounds beyond 75 yards, not to mention resulting horseshoe trajectories.

The .300 Blackout is most effective in rifle-length barrels, pistols giving up approximately 10 fps for every inch of barrel removed from an 18-inch start (somewhat less when loaded with hotter pistol powders). That said, short-tubed AR pistols remain highly popular as maneuverable “truck guns,” particularly on Texas private lands where roads are “corned” and hogs often shot from moving vehicles – perfectly legal in the Lone Star State. 

The test firearm was the Alexander Arms Highlander Pistol, including shoulder “brace” with threaded 10½-inch barrel, holding Rebel Silencers’ SOS Hunter suppressor, was used during my most recent Texas foray. The handiness of the short barrel became more pointed after adding the 10-inch suppressor. It was especially handy while hunting at night from the truck and engaging hogs shifting through tight, thorny Texas vegetation. During that week-long hunt, the Highlander functioned flawlessly. For load testing the Trijicon thermal unit used in Texas was exchanged for Swarovski’s AR-ideal 1-8x 24mm Z8i scope set in Precision Hardcore Gear Black Opps 30mm rings.

Cartridge Assembly

 The Blackout includes an average case capacity of 26.5 grains water. By comparison, the .223 Remington averages 31.9 grains. The Blackout utilizes small rifle primers, Federal Premium AR Match (GM205MAR) primers used in all accompanying loads. One Blackout concern, especially with subsonic loads, is initiating ample expansion at velocities slower than many bullets were engineered to provide, though many companies offer Blackout-specific designs (see Barnes and Cutting Edge bullets).

Hunting bullets in weights from 110 to 230 grains were chosen (no FMJ, target or varmint numbers), though all would also serve for self-defense. Blackout-compatible propellants include fast burn rates found in designated pistol, rifle powders typically fueling smaller varmint rounds like the .22 Hornet and Blackout-inspired powders like Hodgdon CFE-BLK, Accurate 1680 and Shooters World SOCOM and Blackout. All supersonic loads were tested at 75 yards, in diffidence to the 10½-inch barrel, although most would have performed fine at 100 yards. Subsonic loads were shot at 50 yards, where energy delivery remains above 500 foot pounds.

Shooting Results  

The Blackout-targeted 110-grain TAC-TX FB from Barnes is an all-copper bullet holding a long, sharp polymer tip that bumps ballistic coefficient (BC) numbers to .289. Loaded for a T/C .30-30 Contender pistol with a 14-inch barrel, they have proven extremely accurate and trustworthy on large, wild boars. This bullet shot sub-one-inch groups with all powders tested. Best groups with each propellant included .69-inch with 19.5 grains of Hodgdon 110 (2,174 fps), .74-inch with 19 grains of Hodgdon Lil’Gun (2,269 fps) and .55-inch with 16 grains of Accurate No. 9 (2,063 fps).