THE ENERGY EFFICIENT AR WHETHER IN SUBSONIC OR SUPERSONIC TRIM, THE .300 BLACKOUT DEFINES “PURPOSE BUILT.” here seems to be a rifleman’s law, you can’t like a certain cartridge without hating another. If shooters say they like the .280 Rem or .375 H&H, they have to point out they hate the .270 Win or .375 Ruger. Seems odd somehow, like saying you hate a TV show or movie. It takes no effort whatsoever to just not watch it. Personally I don’t dislike any cartridge, though I admit to being puzzled at times what niche they fill. One recent example is the .300 Blackout. A good way to learn about a cartridge is to read about it. Another is to actually shoot it—which is more fun. The .300 Blackout was SAAMIapproved in 2011, based on specifications from Advanced Armaments Corp. (AAC). Its roots go back considerably further. Back in the 1990’s J.D. Jones developed the .300 Whisper, which is virtually identical in appearance and ballistics. J.D. was an early proponent of handgun hunting, an indefatigable experimenter with the energy and resources to get many of his ideas into production through his business, SSK Industries. Certainly he is one of the most influential figures in the world of handguns and cartridge design. Both cartridges are based on the .221 Fireball case. Some sources say the .221 Fireball was a shortened version of the “parent” .223 Rem. Quite a trick, since the Fireball was announced as a commercial cartridge two years earlier than the .223. Actually both cartridges, along with the .222 Rem Mag, resulted from experimental work done by Remington in the mid-to-late 1950’s. All are descendants of the .222 Rem, one of the very few cartridges in which the designers started from scratch. The Fireball case was designed to hold about as much powder as was compatible with the 10-3/4-inch barrel of the original Remington XP-100 bolt-action handgun. Water capacity varies with brass thickness, but in approximate terms, the Fireball holds 20 grains of water, the .222 Rem 24 grains, and the .223 Rem about 28 grains. According to J.D. Jones on his SSK website, among the parameters of the .300 Whisper were (1) compatibility with the AR design and magazines, (2) a heavy-bullet subsonic load for use with a suppressor, and (3) a lightbullet medium velocity load. The .300 Whisper meets all these goals (as does the .300 Blackout). T DAVE ANDERSON Accuracy results from the HPR 110-grain TACTX load (above) and the SIG Elite 125-grain OTM (below) show the potential of the .300 Blackout. THE QUIET SIDE A quality suppressor can effectively reduce the muzzle blast of even powerful cartridges such as the .338 Lapua. As long as the bullet stays supersonic, there’s nothing can be done to muffle the sound. Anyone who’s manned the target pits while shooters fire from 1,000 yards knows a supersonic bullet makes a loud crack as it passes overhead, followed a couple of seconds later by the distant, relatively mild report of the rifle. Keeping a bullet subsonic is no The rifle used for Dave’s .300 Blackout range session was built from parts by Mike Nason. It features Yankee Hill lower and upper receivers and barrel, MagPul stock, UTG Pro Super Slim handguard, CBR handgrip and an EOTech QD sight. 14 WWW.GUNSMAGAZINE.COM • DECEMBER 2015
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