Today i got caught flat footed at the range while i was shooting some steel cased tula 55 grain. The extractor tore off a piece of the rim and caused the case to stay in the chamber and i did not have anything to take it out with. The rifle is fairly new with only 250 rounds through it and prior to to this happening i was firing some q3131, only about 30 rounds, however. The gun has had a mix of tula, q3131, and federal bulk 223. From inspecting some cases i can see some scratches on some cases, a few have dents, and the steel cased ammo has visible carbon on the outside of the case. Some also show marks on the case head.
Details:
Psa 16" midlength upper, .078" gas port
H huffer
Stock spring
Bcm bcg
It did not take much to get the case out when i got home, i uses a wooden dowel that fit very snuggly in the bore and with a few taps with a 2.5 pound weight it came right out. The bcm bcg was purchased brand new from bcm and as far as i know it does not have the o ring installed, i have never taken apart the bolt. Was it just a bad case or could the extractor be providing to much tension?
The dents in the brass cases look like dents from hitting the shell deflector. The scratched being linear, look like mag lip scratches from being stripped from GI mags. Are you using GI mags?
I’ve heard/been told/read mixing in steel after shooting brass can cause this, but I’ve never personally had it happen. I’d clean your chamber and stick to one type during a session. If it happens again after that, you may want to have your chamber gauged.
I do t want to get out of my lane, so I’ll just say there are lots of mixed theories, but it is generally considered a bad idea.
The dents and scratches look normal, but in the pic of the brass case heads, are they damaged? They look pulled on one edge but I can’t tell on my phone?
If they are, then like F2S said, you’re chamber appears to be undersized.
OP:
FYI, A similar “stuck-case” happened to me back when I had a new AR and got some Tula ammo to go with it (I had shot Brass-cased before).
Nowadays I always carry a cleaning rod with me incase I get another stuck, but after Hundreds and hundreds more rounds (Tula/Wolf) it never happened again.
Before, I would have said it was a myth, but… it is exactly what happened to me. It Never happened again, though.
Well, that’s why I hesitated there, because its never happened to me and I do it (mix) from time to time, but for the purposes of helping diagnose, it seems like a good starting point.
Steel case cheap ammo can have issues all its own, but I shoot a couple cases of it a year and rarely have a stoppage. It’s biggest drawback is its just filthy.
I’d clean it and stick to one ammo type and see if it happens again, personally.
yes the case heads are a bit damaged. I could not get a really good picture of it. They indeed are “pulled” on one edge, it also looks like something clawed at it. How would an undersized chamber produce this.
Cases swell after ignition to form a seal in the chamber. A tight chamber will not allow the cases to “shrink” or relieve enough pressure before the bolt unlocks and extraction begins. So, your bolt is clawing at a case that is still swelled and ripping the rims. It could be other issues, but this seems most likely.
It usually happens with higher pressure ammo like full 5.56, though, not Tula.
They make a field gauge that drops in to check your chamber, but if its new I’d call PSA and make them deal with it.
Steel case don’t obturate very well and gasses get into the chamber and leave carbon deposits. A brass case will obturate and firing a brass case after loading up the chamber with carbon will press the carbon against the chamber walls. Follow that up with firing a few more steel cases, which has more stiction than brass (carbon is sticky too) and your setting yourself up for a stuck case.
When the extractor rips the case off, don’t drop a rod down the bore and start pounding on it with a hammer. Take the rod and toss it down the bore and let the momentum do the job. It may take a few tries but it works. Pounding on the rod can lead to complications from bending and other things. I’ve driven out a few stuck cases with no drama by simply using a solid piece of drill rod about 12" long that just fits freely and just tossing or dropping down the bore
Both of those might be overkill. My BCM midlength only needed a Sprinco white with a C buffer, it shortstroked with an H1 added. I run a Sprinco blue with H1 in my LMT. I’ve read Tula is know for cases keeping ripped apart on extraction. I’ve never had that happen with Wolf, Brown Bear and Silver Bear. I’ve got about 15k total through my gun and about 12 of that is steel case. I did have 2 stuck cases at twice and changed my extractor spring each time. I now keep a few of those on hand and change every 3k or so.
I was inspecting some more cases and a few have visible indentations on the rims from the extractor and one has a very noticable indentation on the head from the ejector. This means early extraction which means overgassed correct?
Those last pics with the ejector marks, and the line from the extractor look like overpressure indications. Were those factory or reloads? Could be a chamber problem causing the overpressure given the earlier problems. But the two may not be related at all. Hows that for a non-answer?
Are the marks around the cases (about 1/4" or so from the rims) simply marks or are they the beginning of case separation? They look very much like the cases are stretching and nearly separating in the first and third photos.
I probably should have mentioned this earlier, but I have never cleaned it since I have had it other than wiping down the BCG. Out of the 250 rounds through it about half has been Tula.
They are factory Winchester 5.56 q3131.
I did not notice any case head separation when I looked at them but I will check again. I believe that just might be the taper before the rim.
