I've been digging into the idea of using cast in my Garand, partly for savings on bullets, mostly for a light practice load. After searching here, decided to give it a try.
I've got a RCBS mold that throws a 150-grain gas-check flat-nose bullet, originally bought for .30-30, that's also worked out nicely in .30-06, .308, 7.5x55 Swiss and in a M39 Finn Mosin Nagant. So, being chea- er, just wanting to see if it'd work in the M1, tried it. The load I started with is that bullet, sized .309, over 34.0 grains of IMR4895. Five rounds of it, five with 35.0, five with 36.0. Five because this was to see if A: that bullet would shoot at all well in it and B: to see if these would cycle the action.
The first round of 34.0 didn't move the bolt back quite far enough to pick up the next cartridge but did eject the empty; the next four functioned fully. The 35 and 36 loads all functioned with no problem. Recoil with all was light, and at 30 yards(indoor range, no time right now for outdoor) came in with 2.5", 1.5" and 2" groups(in that order). All hit about point of aim at that range, but no doubt will have to raise the sight for 50 & 100 yards. And with the first two, the cases all landed about two feet to the right; the .36.0 load tended to eject forward and a touch left.
A very successful experiment overall. Now to load up some more and hit the longer range.