April 25, 2016

That Doesn't Look Right

This past Saturday, being a blue-bird day in East Central Indiana, I took advantage of the fact that I was (mostly) caught up on chores and decided to head to the range for some much needed recoil therapy.

Took the Glock and the AR-15, left everything else at home, and grabbed ammo cans for each, targets, and the range bag.

Started out with the AR at 50 yards, and loaded a box of Winchester White Box 5.56 NATO into a new magazine I'd bought a while back but never used before.  This was a cheap imitation of a PMAG that I'd picked up somewhere or another for, like, 7 or 8 dollars.

Loaded the magazine, chambered the first round, sent it along... Hrm, about 2 inches low at 50 yards.  Sent two more, all three about the same spot.  OK, dial up the scope a bit, 10 clicks then back down 2, send another.  Ah, now that's better. let's commence to commencing.

BANG

BANG

*click*

OK, what's this?  Light primer strike, I suppose.  NBD, right, just a chance to practice malf technique.
Safety on, drop the magazine, pull the charging handle to clear out the...

What the hell?

The round looks like the bullet was forced back into the cartridge. Very odd.

Set it aside, put the magazine back in the gun, chamber a round...

BANG

BANG

BANG

*click*

OK, now this is getting to be annoying.

Safety on.  Drop the mag.  Pull the charging handle...



Two rounds from the same box of WWB did this.

I unloaded the rest of the rounds from the cheap-o magazine, put them into a proper Magpul PMAG, and they ran fine, as did a few other boxes.

Wondering what caused this.

2 comments:

Will said...

Did you compare that brass to other rounds in that box, both fired and unfired?

Could be they weren't crimped during manufacturing.

Alternatively, could be that the cases weren't tempered, leaving them too soft to hold the bullets from shifting, even with crimping.

The alternative is that the mag follower is sticking or tilting, allowing the bullet nose to impact the ramp incorrectly, causing all the bolt energy to drive the case over the bullet.

Bear in mind that more than one of these factors could be in play together. Chasing down multiple variables can be a real headache.

Jeff B said...

"The alternative is that the mag follower is sticking or tilting, allowing the bullet nose to impact the ramp incorrectly, causing all the bolt energy to drive the case over the bullet."

That was my initial thought.

I dropped the two rounds at my local gun shop, asked the armorer to dispose of them safely. So I don't have them for analysis any longer.