A lot of people have reported very successful results with Varget in their M1a’s but I am not one of them.
I tested a lot of Varget in one Match M1a that I own and determined that my lot was too slow for my rifle. My lot gave me case head separations.
This particular rifle just seems to be an early unlocker, which makes it hard on brass, so I installed a Schuster vented gas cylinder lock
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=699378 to delay unlock.
Still, the fact that I had problems with Varget in my rifle indicates that it may be marginally too slow for some M1a’s.
Shame as Varget is a superb powder in the 308.
I think an excellent 308 load will be found between 42.5 grains and 43.0 grains.
My recommendation for a powder in the M1a is IMR 4895/H4895/AA2495. IMR 4064 is the slowest I would go.
M1A Match, Douglas 1:10" Barrel
168 Hornady Match 41.0 grs Varget wtd Lot 4295 Mixed LC WLR OAL 2.8
3-Oct-05 T = 87 ° F
Ave Vel = 2486
Std Dev = 19
ES = 61
Low = 2447
High = 2508
N = 12
poor accuracy
168 Hornady Match 42.0 grs Varget wtd Lot 4295 Mixed LC WLR OAL 2.8
3-Oct-05 T = 87 ° F
Ave Vel = 2541
Std Dev = 17
ES = 51
Low = 2514
High = 2565
N = 12
168 Sierra Match 43.0 grs Varget wtd Lot 4295 Mixed LC WLR OAL 2.8
3-Oct-05 T = 87 ° F
Ave Vel = 2604
Std Dev = 15
ES = 49
Low = 2581
High = 2630
N = 20
Good accuracy
case head separations too slow for M1a
