I had a partial case head separation using a 1.8oz buffer

[LRRPF52]

Lots of discussion here about Lapua brass and frankly I think it has gone sideways into a strawman argument thanks to the persistent arguing of one person (no offence). Just because the case has the most visible indication that something went wrong does not mean it was the cause of it.

We still don't know whether this was an in-battery or out-of-battery situation, and we also don't know whether headspace was in spec prior to firing. Headspace of the chamber/bolt combo, and headspace of the loaded case. We only know headspace is out of spec now. For a bolt to be in one piece after a catastrophic failure; the extractor is still OK, but out of spec now with a NO GO gauge introduces one possibility that the bolt was out of spec to begin with.

Another piece of info is the stretch of spent cases is .001", which is typical of bolt gun sizing. This introduces the possibility that the blown case might have had so little headspace that it interfered with the bolt trying to close. Yet closed enough to permit firing.

The load was compressed, and whether we think the amount is 'hot' or 'OK' is less important than it was compressed, with all that implies about changing expected pressures.

Regardless, I think we should move away from Lapua being a suspect brass manufacturer - for the simple reason they are not. Something other than brass manufacturer caused this.

Agreed. He successfully fired other loads through the firearm as well if I understand correctly, but also had Failure To Fire/Active Primer, difficult extraction of that cartridge. That’s either a firing pin protrusion issue, failure to go into battery, inactivated primer, or headspace on both too short or too long ends.

I will also point out again that 30 out of 40 published and pressure-tested max loads from Hodgdon’s are compressed.

Interestingly, only 4 of those 30 compressed loads reached 50,000psi, the highest being 50,100psi. Most of them are 49,900psi or less.

Several of the non-compressed loads exceed 50,000psi. Powder type was more factorial in whether 50,000psi+ pressures were reached.