Neck Splits

[Skyshot]

A friend of mine showed me some cases of a 22-250 that had vertical splits in the neck about half way from the mouth to the shoulder. The top third of the case was smoked up quit a bit. This was new brass, he was using a charge of 32. grns of H380 loading 55 grn nosler bt's. He also loaded with the same brass and bullet a charge of 32.5 grns of BL-C(2) and they showed no ill effects. I was thinking that the H380 load was just not enough powder charge to allow the neck to expand causing the gas to flow around the top of the case. He said the smokey loads shot in an inch and didn't notice the splits till he got home. What do you all think.

 

[243winxb]

Vertical splits in the neck about half way from the mouth to the shoulder happens in new brass. Poor quality brass is my guess. Nothing to do with the loads. The chamber could be oversize in that area and not supporting the brass. The load with the most pressure would split first.

 

[MEHavey]

A semi-no-brainer: Your friend needs to anneal the neck shoulder section of the cases (new or not). The H380 load is low (35k psi) so I'm not surprised that the cases didn't totally seal upon firing. But then again the BL/C2 load isn't that much higher (37k psi).

In any case, the necks aren't splitting due to pressure (or lack of it). They're splitting because the brass is hardened/brittled/never properly annealed to start with (which didn't help sealing either).