Gun issue or coincidence?

[profjeremy]

I took a new gun to the range yesterday and shot various types of factory ammo through it. I did notice a few fireballs while shooting, but didn’t think much of it. However, when picking up my brass, I noticed the two casings in the pic.

I probably would have written this off to ammo, except that they are two different brands of .45 ACP ammo (Underwood 230gr +P and Speer Lawman 230gr TMJ). I can’t recall ever seeing any cases in any of my guns ever do this before, so given that it was two respectable brands of ammo that I had the same issue with, I wondered if it was the gun.

Since the INGO community has taught me so much, I figured this was another opportunity to be educated!

 

[profjeremy]

The only other thing I could think of… those magazines were a beeyotch to get loaded, some of the most ridiculous springs ever! Did I maybe weaken the cases when I was cramming them into the mag and that allowed them to crack?

 

[rosejm]

Is it possible the feed lips scored the case and made a weak spot? Sure. But the chamber should have supported the case anyway, and I'd expect to see the scoring all the way down to the base. I wouldn't expect to see split cases...

Done a plunk test on that chamber with some ball ammo? How's it look/feel?

 

[Cameramonkey]

Change the variables.

Can you take the same batch of ammo and shoot it in a different gun?

 

[profjeremy]

Is it possible the feed lips scored the case and made a weak spot? Sure. But the chamber should have supported the case anyway, and I'd expect to see the scoring all the way down to the base. I wouldn't expect to see split cases...

Done a plunk test on that chamber with some ball ammo? How's it look/feel?

I’ll look at that tomorrow, but I didn’t notice a difference in feel or accuracy while I was shooting… if I hadn’t seen the cracked cases, I wouldn’t have known there was an issue. I am wondering if I didn’t do something to the rounds when I was loading those extra stiff mags.

Change the variables.

Can you take the same batch of ammo and shoot it in a different gun?

Actually will have that option tomorrow! I got this particular gun on a very good deal, so I went ahead and picked up a second one. Definitely going to head to the range tomorrow and shoot them side by side.

 

[Cameramonkey]

Actually will have that option tomorrow! I got this particular gun on a very good deal, so I went ahead and picked up a second one. Definitely going to head to the range tomorrow and shoot them side by side.

Best if you have another in the same caliber. Another identical gun is OK, but would be better if it were a different model/mfr. Another identical gun may not tell us much more than that particular model uses a y overbored ridiculously unsupported chamber.

 

[Sigblitz]

What gun and caliber? It looks like it started at the neck.

 

[Mgderf]

Always possible that it's just bad brass.
Maybe not probable, but still possible.

 

[tsm]

The gun model is …? And, is it a new gun, meaning a brand new recently manufactured, you’re the first owner gun, or is it a used gun and it’s new to you since you just purchased it? If the latter, thinking someone might have badly reamed out the chamber before you got it. Perhaps there’s a reason it was such a “good” deal!

 

[Michigan Slim]

As fast as ammo is being manufactured, it could just be the quality of the brass being put out. I've split many many cases. Magtech was the absolute worst for me. Even new Starline splits once in a bit.

 

[Creedmoor]

Best if you have another in the same caliber. Another identical gun is OK, but would be better if it were a different model/mfr. Another identical gun may not tell us much more than that particular model uses a y overbored ridiculously unsupported chamber.

If it was from being ridiculously unsupported, the case would have blown out just above the rim.
I'm going to guess, hard brass with a warm load.

 

[STFU]

<--- I have split .44 REM previously, but they were cases that had been reloaded several times (by me) with heavy loads.

I am noticing the same V shaped notch at the top of the case on each split. Are there any burrs on the feed ramp or near the chamber that the cases might be getting snagged on?


Does that V shaped notch show up on any cases that did not split?

 

[profjeremy]

What gun and caliber? It looks like it started at the neck.

It’s a CMMG Banshee 5” AR pistol.

The gun model is …? And, is it a new gun, meaning a brand new recently manufactured, you’re the first owner gun, or is it a used gun and it’s new to you since you just purchased it? If the latter, thinking someone might have badly reamed out the chamber before you got it. Perhaps there’s a reason it was such a “good” deal!

It’s new, but I had read that these have had a few issues a couple of years ago. Was hoping that they got it all ironed out, but maybe I also got old stock.

<--- I have split .44 REM previously, but they were cases that had been reloaded several times (by me) with heavy loads.

I am noticing the same V shaped notch at the top of the case on each split. Are there any burrs on the feed ramp or near the chamber that the cases might be getting snagged on?
View attachment 294749

Does that V shaped notch show up on any cases that did not split?

I’m going to go through the cases more thoroughly, but I do think it has something to do with the magazines. I’m not exaggerating when I say that they were the toughest mags I have ever loaded. Perhaps I wasn’t patient enough in breaking those in and need to just load/unload the hell out of them for a few days. Pray for my thumb!

 

[Max Volume]

If mags maybe feed them singly with the same ammo?

 

[tsm]

I’m not suggesting this occurred, but since Banshees come in multiple calibers, those fired cases might look similar to how the case of a 10mm round would appear if it managed to fire in a .45acp chamber. I know you said they’re both .45; I just can’t see how pushing them into a tight mag could contribute to that type of damage (unless you used a vise or hydraulic press instead of your thumb). That’s all I got!

 

[NyleRN]

Wondering if you have a short throated chamber and some of the bullets are getting set back upon entering the chamber thus causing pressures to rise
ETA: What do the primers look like?

 

[Sigblitz]

I was thinking feeding issue and getting pinched. New mags put together wrong, under gassed. Since it's new, send the gun back in with the brass.

 

[NyleRN]

I was thinking feeding issue and getting pinched. New mags put together wrong, under gassed. Since it's new, send the gun back in with the brass.

I'm fairly certain this is a blowback action

 

[Ark]

Seems like an easy diag step would be to load some rounds in a mag and drop the bolt from the bolt release while pointed at a clear barrel. Slowly eject the round without firing (obviously) and inspect the case. Use factory new ammo with pristine cases. See if they're getting gouged or scored.

 

[Route 45]

I'm fairly certain this is a blowback action

It's a radial delayed blowback, not a simple straight blowback.

I don't think the mags have anything to do with this, but curious what brand of mag the Banshee comes with. They shouldn't be that hard to load. Isn't the Banshee 45 Glock mag compatible?