Problems with Rem 223

[ChessRatz]

Thanks to a few CalGuns vendors/sellers, I just finished my first OLL build and shot it yesterday. I shot 40 rounds of Remington 223 (55gr.) that I picked up at the local WalMart since the ammo I ordered didn't arrive in time for me to take to the range. I picked up the brass (of which I could only find 20 pieces) and noticed that 2 of them no longer had the primer

Any ideas as to why? Any suggestions? Anything wrong?

I have a CMMG 14.7" M4 upper with a chrome-lined 5.56mm chamber, 1/7 twist. (don't know if any more info is needed, if so I'll get it posted)

[1lostinspace]

Thanks to a few CalGuns vendors/sellers, I just finished my first OLL build and shot it yesterday. I shot 40 rounds of Remington 223 (55gr.) that I picked up at the local WalMart since the ammo I ordered didn't arrive in time for me to take to the range. I picked up the brass (of which I could only find 20 pieces) and noticed that 2 of them no longer had the primer

Any ideas as to why? Any suggestions? Anything wrong?

I have a CMMG 14.7" M4 upper with a chrome-lined 5.56mm chamber, 1/7 twist. (don't know if any more info is needed, if so I'll get it posted)

Over pressure if this keeps happening with other ammo your chamber is out of spec don't shoot it and if you do keep your hands away from the mag

[l_Z_l]

this might sound stupid but what'll happen if he keeps shooting?

[Jicko]

this might sound stupid but what'll happen if he keeps shooting?

KaBOOM!

And it IS STUPID.... if he keeps shooting it...

[Jicko]

Thanks to a few CalGuns vendors/sellers, I just finished my first OLL build and shot it yesterday. I shot 40 rounds of Remington 223 (55gr.) that I picked up at the local WalMart since the ammo I ordered didn't arrive in time for me to take to the range. I picked up the brass (of which I could only find 20 pieces) and noticed that 2 of them no longer had the primer

Any ideas as to why? Any suggestions? Anything wrong?

I have a CMMG 14.7" M4 upper with a chrome-lined 5.56mm chamber, 1/7 twist. (don't know if any more info is needed, if so I'll get it posted)

Call up CMMG. They probably will take it back and check it out for you..... what you are seeing is a sign of "serious over pressure"... which commercial 223REM shouldn't be....

If you still have the brass, take some macro pictures of them and to show us.... both from the side, and from the bottom (ie. showing ALL the primers)

[Fjold]

Or you have some brass with oversized primer pockets or flash holes. Look inside the cases and compare the size of the flash holes with other cases that didn't blow the primers out of. Sometimes the holes get punched wrong and it lets too much gas into the primer cup and blows them out.

[1lostinspace]

I load 25.3 gr Varget with no pressure signs, so you shooting factory non military m855 or M193 out of a 5.56mm chamber and getting pressure signs then you have a problem.

[!@#$]

lots of problems from cmmg in the last few months.

[bohoki]

stay away from them barrels shorter than 20 inches i swear i hear 95% of the problems from 16 inchers

[ChessRatz]

Here is all the "macro" I could get


I also used some calipers to check the diameter of the brass case. The brand new ammo (same 223 Rem) I have measures .373 to .374 while the empty brass I gathered measures .374 - .375 including one of the blown primer pieces of brass. The other blown primer piece of brass measures .382

The last thing I did was put a small pistol primer (already fired) in the empty primer hole. The primer just dropped in the primer pocket of the brass that measured .382 with no pressure at all. The primer went in (with some pressure) to the other piece. That is all I got. Is it possible that its bad ammo or should I call CMMG? Thanks for the comments so far.

[ChessRatz]

Or you have some brass with oversized primer pockets or flash holes. Look inside the cases and compare the size of the flash holes with other cases that didn't blow the primers out of. Sometimes the holes get punched wrong and it lets too much gas into the primer cup and blows them out.

You might have something there... I measured (as best and critical as I could) the two problem pieces of brass. the worst one had a flash hole that was .091 and the other was .0875 Then i deprimed 5 of the pieces of brass that I collected and those were all a consistent .0835

So the only question is: did the flash hole enlarge due to a problem or was the flash hole too large to begin with causing the over-pressure which blew the primer

edit to add: you can see the larger flash hole in the photo I posted.

[1lostinspace]

You might have something there... I measured (as best and critical as I could) the two problem pieces of brass. the worst one had a flash hole that was .091 and the other was .0875 Then i deprimed 5 of the pieces of brass that I collected and those were all a consistent .0835

So the only question is: did the flash hole enlarge due to a problem or was the flash hole too large to begin with causing the over-pressure which blew the primer

edit to add: you can see the larger flash hole in the photo I posted.

what ammo did you order?

[ChessRatz]

what ammo did you order?

I ordered some Federal XM193 (55gr.) and some cheap Wolf ammo. My XM193 just got here today

[StraightShooter]

Judging by that picture and how all the primers that did stay arent showing overpressure I might say it was just bad ammo with loose pockets. It seems to me that if it was an overpressure issue that the primers on the other cases should be flattened more. The flash hole on the one on the bottom seems oversized to me but that could just be the picture. A flash hole that it too large will cause too much pressure to enter the cup and blow it out.

[jandmtv]

sounds like oversized primer pockets to me, as straightshooter said, the other cases in the pic show no signs of overpressure.