30 Carbine case separation

[gpidaho]

I'm not very experienced with the 30 carbine, having sent only a few hundred rounds down range after picking one up in a trade. Yesterday at the range I had a failure to feed with my Universal M1. I racked the action, still no go. Not being one to force an issue when things aren't working, I trucked the carbine and finished the day with other guns. Up on cleaning the problem became apparent, broken case. The head had ejected and the strait case remained in the chamber. Didn't seem to hurt anything and there was no gas blow back. Should I be more concerned about this than I am? Does this just happen at times when you buy used brass? I'm well aware of what causes case separation, just want to know if it's dangerous to carbine or shooter? Thanks GP

[Artful]

Usually only happens with brass used multiple times or loaded with wrong powder that keeps the gas pressure up while bolt is trying to remove case.

When you say "used" brass is it range pickup or once fired from retail seller of used brass or ???

[gpidaho]

Artful, thank you for the reply. The brass is from a lot bought here at boolits on the S&S but no claim was made as to once fired or the like, just used brass. The boolit in question is only 95gr. and it was pushed with Imr 4227 @ 14gr. I've shot three or four hundred of these without problem. I don't blame it on anything other than just not scraping the inside of each case before I loaded them up. I checked other cases from this group (fired cases) and felt a little hitch in a couple more, will split them tomorrow to see what they look like inside. Most likely just brass off some range floor. No harm done. GP

[303Guy]

In the days before I learned how not to break cases I would only find out when opening the bolt and only the head would come out. I never had any leakage which seems strange as the break would be right at the web.

[jimb16]

Three things could have caused this:
1. headspace problems
2. over-used brass
3. poor quality brass (A-Merc is an example of bad brass)

Get the headspace checked. If it is ok, then the problem is almost certainly the brass.

[gpidaho]

jimb16: Hesdspace is fine. I think you called it with #3, there's about 10% A-merc brass in the lot of used brass I bought. I don't blame seller for this as I'm sure it was all off the floor of some gun range, just part of the deal when using brass when you don't know it's history. Thanks for your reply. GP