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August 16th, 2019

Scary Stuff — .300 Blackout Fired in a .223 Rem Barrel

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56
Photos and Facebook post by Tactical Rifle Shooters

Yet another .300 Blackout disaster. Unfortunately, that .300 Blackout cartridge can fit in a .223 Rem chamber. Shooting a .308-caliber bullet in .223 bore is a recipe for disaster.

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56The .300 AAC Blackout aka “300 BLK”, is a compact 30-caliber cartridge designed to work in AR-15 rifles. It has a shorter cartridge case to accommodate the bigger 30-caliber bullet while still fitting in a standard AR-15 magazine. Unfortunately, that’s the danger. A careless shooter can toss a .300 Blackout cartridge in with .223 Rem rounds without noting. And because the case-head size is the same as the .223 Rem (5.56×45) the rifle’s bolt assembly will happily chamber and fire the .300 BLK round. Problem is, that forces a .308 diameter bullet down an undersized .223-caliber bore. Not good!

This images were provided by Tactical Rifle Shooters on Facebook. The message was clear: “Don’t try to run 300 Blackout in your .223/5.56mm. It won’t end well. The problem is identical rifles and identical magazines but different calibers.”

For those who MUST have a .300 Blackout, here are some things you can do:

1. Use different colored magazines for .300 Blackout vs. .223 Rem.
2. Fit all your uppers with caliber-labeled ejection port covers.
3. Mark .223 Rem upper handguards with the caliber in bright paint.
4. Mark all .300 BLK Rounds with heavy black marker.

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56

Comments by Folks Who Viewed these .300 Blackout Disaster Photos:

“The .300 Blackout is simply a badly-designed round. A properly-designed round would have had a feature in the shape that would have prevented cross loading in the first place.” — D. Santiago

“I almost made that mistake… I had a magazine of 300 BLK inserted in my .223/5.56 all night. Fortunately, I never pulled the trigger. Once I realized the mistake, I almost got ill. [After that incident] I no longer own a 300 BLK.” — B. Welch

“Happened to me hog hunting from a helo. Gun exploded in my face.” — B. Hood

“Fire-forming projectiles [is] so wrong in centerfire!” — M. Stres

“Had some dude come into the store the other day wanting .300 Blackout ammo to shoot in his 5.56 AR. It took 15 minutes of explaining for him to understand you got to have a .300 Blackout Upper!” — R. Williams

Permalink Bullets, Brass, Ammo, News, Tech Tip 20 Comments »
January 30th, 2015

Why Shoot a 300 Blackout? Kirsten Provides Some Answers

.300 AAC blackout blk

In her latest video, Kirsten Joy Weiss shows off the 300 AAC Blackout, a popular .30-caliber cartridge for AR-platform rifles. Kirsten explains the advantages for the 300 BLK for hunters as well as those using an AR for self-defense. The 300 BLK is popular with suppressor owners because it works well with heavy bullets launched at subsonic velocities.

Reasons to Shoot a 300 AAC Blackout:

— You can use your current AR Bolt, Bolt Carrier, Buffer, and Magazine. The only part you need to change is the barrel.
— 300 BLK conforms to state hunting regulations which may require a cartridge larger than .22 Caliber. The 300 BLK shoots .308 caliber bullets.
— Lapua now sells 300 AAC Blackout brass so no case-forming is required. Just load and shoot.
— You can shoot light bullets supersonic or heavier bullets subsonic. The subsonic capabilities of the 300 BLK make it ideal for use with a suppressed AR.
— With a .30-caliber bore and a modest powder charge, barrel life is outstanding with the 300 BLK.
— You can make 300 BLK cartridges from fired .223 Rem brass, which is plentiful and cheap.
— The .300 BLK performs well with some very accurate powders, such as Hodgdon H4198 and IMR 4227.

300 BLK Dan Horner

The 300 AAC Blackout was created by Advanced Armament Corp. and Remington primarily for the military as a way to shoot .30-caliber bullets from the M4/AR15 platform while using standard magazines. As explained by Robert Silvers, AAC’s R&D Director: “Now there is a way to shoot 30 caliber from your AR while still using normal magazines with full capacity. Even the bolt stays the same, and all that changes is the barrel.” For more information visit www.300aacblackout.com and download the 300 BLK Cartridge Information Guide (PDF).

300 AAC Blackout SAAMI Diagram
300 Blackout SAAMI Cartridge Specification

SAAMI, the industry standards organization, adopted and standardized the AAC 300 Blackout in 2010. The SAAMI diagram for the 300 BLK is shown above. Lapua now makes 300 BLK cartridge brass.

300 BLK Blackout AAC Lapua brass cartridge

300 BLK for 3-Gun Competition
The 300 AAC Blackout has been touted as an important new hunting round, but we see it more as a specialized “rule-beater” 30-cal option that lets 3-Gun competitors “make major” with a low-recoil cartridge that also offers long barrel life. For those who need to run a .30-caliber cartridge from a standard AR15 platform (as opposed to the AR10), the 300 AAC Blackout makes some sense. But for hunters using a bolt gun, there are any number of tried and true options, such as the 7.62×39, .30-30, and, of course, the .308 Winchester (7.62×51 NATO).

Permalink - Videos, Bullets, Brass, Ammo 14 Comments »