[Dropdeadhippie]

I fired about 50 shots through my brand new 336ss yesterday. I had an extraction jam and found the spent case was split all the way around the circumference (about a quarter inch up from the primer). The casing was in two pieces. Looking at the other spent brass I see a noticeable bulge in all of them ( in the same place where the one split). Do I need to send this gun back to marlin? Doesn't seem right to me but I have limited experience here. Shooting the hornady leverevolutions.

 

[Doc Fillem]

That's not right, it shouldn't bulge brass like that. Send it back.

 

[CalvinMD]

Most definantly an improperly bored chamber...send it back before you get hurt by gas finding its way out ..the Wrong way out!

 

[pisgah]

Without at least a photo of the brass, I can't say whether it is the chamber or the brass that is abnormal. It is quite normal for fired brass to have a slight bulge in the spot you describe, noticeable when compared to unfired brass. This is where case head separation occurs with brass that has been overworked or resized numerous times for reloading.

Was this new ammo, or reloaded? If reloads, try some factory loads. If new, what brand? Defective brass in new factory-made ammo is not unheard-of, and somehwere in my foggy brain I may remember something about similar problems with one lot of Hornady, although that may be my imagination. At any rate, one separation is not cause to send your rifle anywhere right now.. I'd at least try a few of another brand first.