Well...most of us use a 150gr spitzer bullet instead of a roundnose. Perhaps that is what you meant??
Anyways, for either bullet shape 47grs of IMR 4895 should provide a safe load with nearly any military or commercial cases and will provide enough pressure to function the M1's action. Primers can be whatever large rifle brand you happen to have available. No need for large rifle magnum primers, just make sure you've fully seated the primers, (they should be slightly below rim level).
When it comes to loading for the M1, the generally accepted powders are: IMR or Hogdon 4895, IMR 4064, Hogdon Ball C2, Wincester 748, Varget. I may have missed a few, however, these are the most popular.