AR 15 - 2.23/5.56 vs 300 Blackout

bgreenea3 · Post by **bgreenea3** » Thu May 02, 2013 12:40 pm

Bullseye wrote:What is possible is a round of .300 Blk can be accidentally chambered in an AR with a .223 barrel and fired with catastrophic results. Since the .300Blk uses a casing from the .223, with the same external diameter, but is shorter in overall length, it will fit into a .223 magazine and chamber. The 30 cal bullet will not fit into the smaller caliber barrel and this is where the problem would happen.

R,
Bullseye

Would the 300 chamber all the way or would it get stuck and have to get sacked out with a rod? I don't think it would fully chamber.

If the 223/5.56 was fired in the 300, wouldn't it be likely fire form the brass nearly to the 300s dimensions? The pressure would drop off majorly when the bullet left the case since there would not be a gas seal between the bullet and the bore. I've seen 9mm shot out of a 40sw and if it doesn't split the case mouth it look like a reverse bottleneck.

charlesb · Post by **charlesb** » Thu May 02, 2013 12:55 pm

I used to make brass for my 8mm-06 by firing 30-06 rounds in it.

Not saying that it's a good idea - just that I used to do it.

Texasbud · Post by **Texasbud** » Fri May 03, 2013 8:36 am

Is anyone interested in purchasing a brand new, in the box, DDM4 V7 300 Blackout?

Post by **Bullseye** » Sat May 04, 2013 10:42 am

Would the 300 chamber all the way or would it get stuck and have to get sacked out with a rod? I don't think it would fully chamber.

That is part of the problem. The .300Blk cartridge is just short enough that the bolt will appear fully closed but the bolt lugs are not rotated and locked.

R,
Bullseye

bgreenea3 · Post by **bgreenea3** » Sat May 04, 2013 11:38 am

Ahhh I never thought it would get close enough to nearly be in battery.

Hakaman · Post by **Hakaman** » Sat May 04, 2013 12:46 pm

Here's a neat youtube vid:

http://www.youtube.com/watch?v=XXuDfCJzwpY