When I finally decided to go to the dark side, and shoot an AR, I went out and conducted load testing with the commonly used powders of the era.
The primers I used were the nickel plated WSR. When Winchester changed over to the thinner, more sensitive “brass finish” primers, I had to cut loads because the primers pierced. After eating up enough firing pins with the first and last 5000 brass finish WSR I purchased, I went completely over to CCI primers. These loads work perfectly with the thicker CCI and CCI#41 primers.
I did chronograph higher velocities, but after much use I decided that 2800 fps was a good velocity limit in my rifles, so I am not showing the faster data. My upper limit is based on use in 100 F weather out to 300 yards. When I push 69’s much faster than 2800 fps I get blown primers and pierced primers, so that’s my limit.
I know guys who push 77’s faster than I push my 69’s. I don’t know how their cases or rifles hold up and I am not going to try to find out why.
AA2495 is charge for charge the same as IMR 4895. Accurate arms told me this powder duplicates the IMR 4895 pressure. Stupidly they call it AA2495 instead of AA4895, to show that it is a copy. If it is cheaper, go buy it.
You will find that IMR 4895/AA2495 or surplus 4895 shoots exceptionally well with 69’s, 75’s, and 80’s, in the AR.
For a first time reloader, I would try 24.0 grains IMR 4895 with a 69 or 68 grain bullet. If you don't experience any pierced, blown primers and pockets are fine, you could try bumping it up a half grain.
Quote:
M15A2 Armalite 20” 1:8 Stainless Wilson Barrel
69 gr Sierra Match 23.0 grs AA2495 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 52 °F
Ave Vel = 2571
Std Dev = 13
ES = 39
Low = 2546
High = 2585
N = 10
69 gr Sierra Match 23.5 grs AA2495 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 52 °F
Ave Vel = 2670
Std Dev = 14
ES = 41
Low = 2649
High = 2690
N = 10
69 gr Sierra Match 24.0 grs AA2495 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 52 °F
Ave Vel = 2766
Std Dev = 12
ES = 32
Low = 2749
High = 2781
N = 10
69 gr Sierra Match 24.5 grs AA2495 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 52 °
Ave Vel = 2808
Std Dev = 28
ES = 85
Low = 2778
High = 2863
N = 10
|