For a Springfield bolt gun with decent headspace (and not a low serial number) any modern factory loads would be safe. Accurate is another matter and for that there's only one way to find out.
I never knew an "out of the box" M1 that shot as well as a good Springfield. (Personal experience mind you.) Plenty good mind you just not "as good". Bedding protocols can upset that applecart though. Love me an M1, so please no hate mail!😇
I own both rifles and the 03a3 is more accurate.
I also have a decided affinity for the M1.
