I believe sometimes that cratered primers may be due to other factors besides a hot load . My 204 ruger craters every primer slightly. Factory loads handload below book start it don't matter . Shoot I even went as far as a case 3/4 full of trail boss and still got it to crater .
Now what causes this I'm not certain . I'm sure others here can give more insight . This would have been a good question for JE Custom. Rip my friend