Winchester said the slight (2 degree) angle of the locking bolts was to handle the increased pressure from the 348. Buck Eliot’s 454 has vertical locking bolts and he told me the angled bolts in my model 89 500 s&w were a mistake. The first one in built had angled bolts and I tested it. Like sticking cases in it which is over 100k psi according to my friend at Western powders.
