You need to be mindful of powders. Coming from the Garand I only load IMR4895.
I suggest that you do some research on the M1a.
No sense bending the op rod with the wrong powder.
Check out the CMP forums.
yes H 4895 seems to be the common followed closely by the IMR version..
depending on which source you use using the different slightly but use nothing slower burning than 4064 on one source or Sierra is saying 4320...
