I purchased N140 after it had been recommended by a VV rep for M1a’s. I tested it in a bolt gun, using a favorite M1a load with AA2495. My lot of AA2495 was identical for all practical purposes to IMR 4895. Same charge of stick powder AA2495 gave same velocities as a charge of IMR 4895. And Accurate Arms told me that they blended the stuff to duplicate the IMR 4895 pressure curve.
Generally I fire a “standard” load for calibration purposes, so you can compare my standard load against the N140 series.
Under no conditions do I recommend using Federal primers in a M1a. They are just too sensitive. I would recommend using CCI #34, or CCI standard. Winchester changed their primers in 1999, they are now brass colored, and they are now more sensitive. I do not recommend using them in a gas gun either.
Best accuracy was achieved near the 43.0 grain level, but I think I would use 42.5 grains of N140 and see if any thing strange happens when the weather hits 100 F.
While I did not have any pressure signs at 43.5 grains, I get worried when I am pushing a 168 at 2650 fps, because of the possiblity of high temperature pressure problems. I like to keep my velocities between 2575 and 2600.
I don’t use N140 in the 308, I am using it in .223. It is a superb powder in that cartridge all the way out to 600 yards, I am sure it would do equally well in 308. But I have lots of 4895 for that cartridge.
Pre-64 M70
24 " Douglas Barrel 1:10 twist
168 gr Sierra Match 41.5 grs AA2495 thrown, LC72 WLR
30 Dec 1999 T = 58 °F
Ave Vel = 2570
Std Dev = 23
ES = 66
Low = 2552
High = 2618
N=7
168 gr Sierra Match 42.0 grs N140 wtd, Fed cases, Fed210s OAL 2.800"
30 Dec 1999 T = 58 °F
Ave Vel = 2532
Std Dev = 14
ES = 48
Low = 2511
High = 2559
N=10
168 gr Sierra Match 42.5 grs N140 wtd, Fed cases, Fed210s OAL 2.800"
30 Dec 1999 T = 58 °F
Ave Vel = 2598
Std Dev = 22
ES = 78
Low = 2563
High = 2641
N=10
168 gr Sierra Match 43.0 grs N140 wtd, Fed cases, Fed210s OAL 2.800"
30 Dec 1999 T = 58 °F
Ave Vel = 2593
Std Dev = 9
ES = 32
Low = 2577
High = 2609
N=9
168 gr Sierra Match 43.5 grs N140 wtd, Fed cases, Fed210s OAL 2.800"
Ave Vel = 2641
Std Dev = 14
ES = 46
Low = 2616
High = 2662
N=9