300 blackout will chamber in 5.56!?

[Duece McCracken]

Yeah, this is well documented.

I put .300blk labeled dustcovers on any AR in that caliber, clearly label my mags 300 blk via spray paint and stencils for easy identification, temporary labels to further denote subs or supers, and keep all the .300 blk ammo/mags in its own range bag separate from .556/.223.

[NathanB]

I mean it’s brass is made from a. Cut down and reformed 223 case so yeah it’s gonna chamber. I’ve seen the effects of pulling the trigger on it when done too.

I have a rule that ammo and rifles don’t come out at the same time. Especially if there are multiple people around

[P89]

That's why I never had the desire to mess with the blackout round and jumped right into big bore. No screwing that one up.

[Brick]

I learned something new today. Not firsthand thankfully.

Apparently 300 blackout will seemingly load into the chamber of a 5.56 rifle.

Bad things will happen. But the bolt will close.

This is a non issue for me as I don't have 300 blackout. But seriously keep your ammo separated.

-Zach

Sounds like bad JuJu to me! As long as the bullet stayed clear of the leade the bolt might close, but I would not want to be around!

[Ronin]

This has been a known issue since 300 BLK hit the market. Here's a thread on Arfcom about a guy that blew-up his Geissele Super Duty 5.56 shooting 300 BLK. It's a long thread, but Bill Geissele does a breakdown analysis of what happened. And he replaced the guy's gun.

[alpacaheat]

This has been a known issue since 300 BLK hit the market. Here's a thread on Arfcom about a guy that blew-up his Geissele Super Duty 5.56 shooting 300 BLK. It's a long thread, but Bill Geissele does a breakdown analysis of what happened. And he replaced the guy's gun.

Great customer service.

Man that forum's format is horrible to look at.

[alpacaheat]

[ShooterInPA1]

This is why I keep my 300 BO mags in a separate container and marked 300 BO only with a Sharpie.