OP, I'll save you months and years of headache right now. The answer is "No". At best you're talking a 1-1.5 MOA rifle.
Caliber selection is limited by the gas system. The op-rod can't handle port pressures caused by the powder used in most cartridges (that actually would fit) under 7mm. 6.5 PRC is an immediate no-go because of the bolt face diameter, the magazine, clips, etc... Even the 6.5 Creedmoor is going to take some work; adjustable gas cylinder or light bullets with Varget, potential feeding issues... And you gotta find someone to spin up a barrel for you. Timed receiver threads, timed gas cylinder splines, gas port, hand guard mounting interfaces, extractor cuts, feed ramp cuts etc... It's not a simply contoured barrel. You'll have to decide which handguard(s) to keep and omit, and come up with some way to bed the rifle.
After all of your hard work you'll have something that is both ugly and performs with mediocrity next to modern semi-autos.
I'd like to see what the M1c/d models could do. Would be fun to take one out shooting steel!
I've never read or heard a favorable first-hand account of them from soldiers/Marines that were issued them. Maybe an acceptable DMR style rifle in WWII/Korea, but very quickly obsolete, and never a true LR/"Sniper" rifle. I'd guess 1.5-2.5 MOA with issued ball/AP ammo. Both the C and D models leave something to be desired in optics mounting hardware, let alone the optics (2.2-2.5x).
Don't fool yourself and butcher a piece of history in the process.
Even a 6.5 Creedmoor M1a is more trouble than it's worth.