4seventy, It sure SOUNDS like excessive headspace!! Iif not, it sure is a mystery!! Glad you got your mone back!! I have been shooting my own reloaded ammo now since 1954, in calibers from .22 Hornet all the way up to .50/110 Win., including a number of different magnums, and have never seen anything like your experience. I have seen some blown primers, but I knew what had caused it!!

iqbal, I'd be willing to bet your buddy's brass was too long for the chamber in that M 70. When he jammed it in, he created a situation wherein the case neck could not expand enough to freely release the bullet!! This caused his "big kabamm!!" Hope he wasn't hurt!!