My personal favorite load with the M1
Garand is a 168 Match (any brand) 47.0 grs IMR 4895, any case, CC#34, OAL LT 3.30”
AA2495 gives identical results, and when it was cheaper, I used kegs of it.
I conducted testing of IMR 4064. IMR 4064 is an excellent powder, but it is the slowest I would use in a Garand. It is also long grained so it does not throw as well as IMR 4895/AA2495/H4895.
I would use a charge not to exceed 48.0 grains with a 168. My chronograph data, including data from a 26” match barrel, is below.
Second question will I need to get an adjustable gas plug for the above load recipe and how do I set that up if needed.
My loads are totally appropriate with the Garand gas system. If you shoot commerical ammunition with its too high of port pressures, and too slow powders, then you will need to consider an adjustable gas cylinder lock screw. However, if you roll your own, use IMR 4895/AA24956/H4895/AA2520 (a ball powder), use proper loads, you will not need to mess with an aftermarket lock screw.
Code:
M1 Garand Douglas Barrel 1:10 twist
168 Sierra Match 47.0 grs AA2495 wtd WLR FC Cases OAL 3.30"
5 May 00 T = 82 ° F
Ave Vel = 2632
Std Dev = 16
ES = 50
Low = 2616
High = 2666
N = 10
168 gr Sierra Match 48.0 IMR 4064 wtd LC66NM WLR OAL 3.30"
5 May 00 T = 82 ° F
Ave Vel = 2594
Std Dev = 18
ES = 38
Low = 2575
High = 2613
N = 5
M98 26" 1-10 Wilson Barrel
168 gr Sierra Match 48.0 IMR 4064 wtd LC66NM WLR OAL 3.30"
5 May 00 T=82°F
Ave Vel = 2653
Std Dev = 9
ES = 27
Low = 2645
High = 2672
N = 9
150 gr FMJBT TW 56 Ball
24 Mar 04 T= 70 ° F
Ave Vel = 2680
Std Dev = 31
ES = 78
Low = 2620
High = 2698
N = 6