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

[LRRPF52]

Hornady says 29.1 grains is max with that combo, but both QL and GRT say that's a 64,000 plus PSI load.

Nosler says 29.5 grains with their 120 gr BT.

Weird.

The difference is that Hornady, Hodgdon’s, Alexander Arms, Sierra, etc. actually tested their loads in calibrated pressure test breeches, whereas QL and GRT entered numbers into a theoretical program with no actual measured data, which is meaningless and invalid.

The Alexander Arms published max load with Lapua brass even with 129gr SST is 29.4gr of AA2520, CCI450, 2.260” COL.

123gr Scenar max load with AA2520 from AA data is 30.7gr using CCI450, 2.260” COL.

From Hodgdon’s, it’s 29.5gr under 123gr Scenar at 2.260”, using Winchester SRP and Alexander Arms brass (Lapua) 51,800psi.

Hodgdon’s also shows 29.6gr AA2520 under 123gr SMK at 51,700psi.

Nosler shows 2.245” COL with 120gr Nosler Ballistic Tip, Nosler brass, Rem 7.5 SRP, 29.5gr max.

52,000psi isn’t going to cause case failure in brass that’s rated to at least 60,000psi yield strength, which has a Factor of Safety built into that number as well.

We need to see the case.