One more thing to consider...

Accuracy International rifles have a huge firing pin hole. With just about every mid range load and up, I get cratering.

May moons ago David Tubb blew up an SR-25 in 260 doing load development. The gun came apart but the brass/primer looked fine.

I measure case head diameter in extractor rim cut so I can tell if the pressures are high. Easier than measuring the insides of primer pockets.