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

[BluntForceTrauma]

I think Bill Alexander was thinking that if one wants to maximize the powder capacity of the 6.5 Grendel case, the best way — he called it an "old artillery man's trick" — is to reduce the web thickness. But, then, the engineering logically followed that the feed cone of the chamber design must be altered to compensate for this.

Everything is fine when properly engineered; when the chamber is dimensioned to mate with the case. Companies that don't bother with the details, well, they experience issues. This is analogous to the details required for dedicated Grendel bolts and extractors and magazines.