I've also been wondering the same thing myself. Two years and a couple of thousands rounds later....I think I found the answer......
I've shoot mainly mil-surp, so the oprod factor is moot.
I've also deer hunt with the M1.
+1 on just using enough off the shelf ammo to sight in your gun and get the job done. I think I've only put roughly 100 rounds of commercial ammo through my M1, and no problems yet. But its not 100 rounds at the same time. About 1 "clip" to sight in; 1 "clip" just because.....and about 1 or 2 shot during the actual hunt. If I'm bored, I might finish off that clip too.....so give or take, about 24 rounds of commercial ammo per hunting season.
p.s. I've been using the Federal Powershok 150gr softpoint as hunting loads in my M1. Cheap and accurate. So far, no complaints......just dead deer.