Thread: headspace in a break open rifle

The reason the case fails at the web is that it is the point where the head taper meets the 'straight' section of the case wall - a weak point for stress. Any pull forward (case stretching forces) in this area creates a short section of thinning which results in the failure groove that appears at the web. Assisting this is a minimum size case/maximum size chamber situation which blows the weaker section of the case wall out and sometimes you can actually feel a little 'step' in the case head to wall junction area. That's gotta be good for case life...

The other common non-catastrophic failure modes are neck splits, primer pocket loosening and shoulder splits. I've seen a case head failure in a break action rifle, but I never found out what the causes were and I suspect it was not factory ammo. Reloading and oversizing the case (pushing the shoulder back) is the biggest thing that we do that contributes to case failures like this, and the long winded rambling speech here is really just to say that the action type really doesn't have that much bearing on case life so much as how we treat the brass and how good our reloading practices are.