I'll make it easy on you. I knew of this problem over 12 years ago and talked to Arne about it first after shooting the first 6.5CSS I had and then talked to Bill Alexander about it after the first 24" aa barrel.
Lapua modified their 220 Russian case to make the 6.5 grendel case. The 220 Russian has a max operating pressure of 51,000psi. That is why the Grendel has a max operating pressure of 52,000psi. That is why they said do not try to push the pressure on the Grendel, thin brass and bolt strength.
