I've always get about twice the number reloads out of commercial brass that I did out of military brass. The military brass isnt worth the extra work for me either. The biggest problem I've had with M1's and M1A's and brass has been the case mouths getting tore up from bouncing off the concrete pads at our range. Other than that, they are no harder on brass than any other rifle.
The one thing you really need to watch with these rifles and reloading is the primers. Use a hard or mil type/spec primer, like CCI and make sure your depths are right. You dont want high primers. Once you know what your looking for, you can usually tell by finger touch, but a piece of glass or better yet, a mike, will tell you for sure. This is also one of the pains with using military brass and having to either ream or swage the pocket and making sure its right. You dont have to deal with it with the commercial brass.
Make sure you full length resize and trim each time and start checking for case head separations at around 4 reloads for military and around 8 for commercial brass. I usually never got more than 6 reloads out of the military brass where I would get 12-15 reloads out of Federal or Winchester brass as long as the case mouths held up. That is from the same rifle.