Missouri Whitetails - Your Missouri Hunting Resource banner

223/5.56 can chamber a 300 black out

1800 Views 20 Replies 12 Participants Last post by  fishshooter
Just FYI if you have a 223/5.56 AR an unfortunate individual found out it can chamber a 300 blackout round.

Firing it will blow up the gun

Be careful and keep your ammo separate, marking loaded mags isn’t a bad idea

The bullet went a few inches into the barrel before it blew, an Armorer drove it out off the barrel with a cleaning rod and it looked like a 3 inch long .223 bullet

They also recovered the head of the brass and it was stamped.300

Someone had given the shooter a bag of bulk .223, the shooter wasn’t checking them
  • Like
Reactions: 4
1 - 20 of 21 Posts
Thanks Fishy
Picktures ,,I need picktures i wanna see that 3 inch long 223 lordy lordy
I saw this video on this very topec a few months ago:

Picktures ,,I need picktures i wanna see that 3 inch long 223 lordy lordy
See if ole boy will send it to me tomorrow
Day Drinkin At The Range And Roll Your Owns.... don’t mix.....
Details, details. Someone wasn't paying attention to details.
It would take a really short bullet, or a lot of setback in order to get it to chamber. Even the video above states they used a 110 grain bullet, hand loaded. So I guess it is possible, but you have to go outside the boundaries of what is meant to be for the 300 blackout. Here is a sportsmanlike tip for those who don't know......Firearms can be dangerous if you do stupid things, and nobody is immune to that!!!!!
  • Like
Reactions: 4
I never compared the 2 dimensions. This is potential with many different bullets if they are not crimped well. The bolt will simply seat the bullet deep while closing.

Musical instrument Human body Office supplies Writing implement Wood
See less See more
  • Like
Reactions: 1
I never compared the 2 dimensions. This is potential with many different bullets if they are not crimped well. The bolt will simply seat the bullet deep while closing.

View attachment 142153
That's exactly what I got to thinking, we have .243, 6mm, and 7-08 and they are all very similar. Always look at the head stamp as you load.
A .308 will chamber in a .270, also, due to the ogive of the bullet, and the case heads being the same diameter. It really, REALLY pays to be careful and pay attention to what's going into your rifle.
  • Like
Reactions: 1
A .308 will chamber in a .270, also, due to the ogive of the bullet, and the case heads being the same diameter. It really, REALLY pays to be careful and pay attention to what's going into your rifle.
I'm guessing the result would be similar, .03 is less than .07 but guessing not enough that overpressure doesn't rupture something. Thank goodness AR's blow out the mag well.
If you have a 308 round go off in your 270..... a LOT more damage is going to occur than you are gonna want to experience. That would be a bad day
IIRC, a 7mm Mauser (7x57) can also chamber in a .270, and would also cause an ugly incident, which no one would want. I noticed that it could happen, and got rid of the 7 Mauser because I don't need that kind of excitement in my life.

Let's all be careful out there.
  • Like
Reactions: 1
Saw a Browning BAR in 7mag that someone had fired a 7 Express (280 Rem) in and it blew it up. The case is so much smaller that it ruptured in the chamber. Destroyed the gun, blew out the reciever, shredded the forearm, etc.
Saw a Browning BAR in 7mag that someone had fired a 7 Express (280 Rem) in and it blew it up. The case is so much smaller that it ruptured in the chamber. Destroyed the gun, blew out the reciever, shredded the forearm, etc.
As my old platoon sergeant used to say "Son, you gotta be smarter than your equipment". It was good advice then, and still is good advice.
As my old platoon sergeant used to say "Son, you gotta be smarter than your equipment". It was good advice then, and still is good advice.
Or as the saying goes:
"Remove all warning labels and let the stupidity work itself out."
  • Like
Reactions: 2
If I remember right a 300 weatherby will chamber in a 300 win mag, I can recall being at a gun shop when a kid came in and said I think they sold me the wrong shells. Kid went to a big box store and had a 300 Win and said he needed some 300 shells, they handed him 300 weatherby shells. Glad he was paying attention.
If I remember right a 300 weatherby will chamber in a 300 win mag, I can recall being at a gun shop when a kid came in and said I think they sold me the wrong shells. Kid went to a big box store and had a 300 Win and said he needed some 300 shells, they handed him 300 weatherby shells. Glad he was paying attention.
You are backwards on that, 300 win mag will chamber into a 300 Weatherby and rumor has it that it can actually be safely fired in the Weatherby chamber* since the winchester case neck is long enough to get into the throat of the Weatherby.

*Do you own research before trying this, don't take my word for it......
1 - 20 of 21 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top