Back in the mid 70's when I started High Power Rifle Silhouette with a Ruger 77 HB in 308 I did a search for loads. I found that Lones Wigger used a 308 load for Palma shooting and won many medals. The load was 39.0 grains of IMR 3031 with Sierra 168 MK bullets. I loaded up some to try in WW brass with WW lg rifle primers at 2.800". They shot consistent sub 1/2 MOA groups at 100 yds. I used that load for years in HP Silhouette until moving on to the 7-08 in the early 80's.
Still used IMR 3031 in the 7-08, 37.0 grains, necked down WW 308 brass, WW LG primer, Sierra 168 MK at 2.800". It was a great sub 1/2 MOA load in 2 Remington 700 rifles, both a BDL Sporter and a BDL Varmint. Shot that same load in a custom HART barreled 40X 7-08 and was fantastic, with with sub 1/4 MOA groups.
I have played with it in a 223 AR HBAR, and best groups were with 22.5 grs IMR 3031 in military brass, WW small rifle primer, 69 gr Sierra MK, at 2.250". Average fps was 2630 with 20 fps ES. Shot decent, 1 MOA or just under, but other powders were more accurate and had higher fps. But if you just want to burn up the 3031, it can be useful. Sorry I didn't use any other bullet weights with 3031.
Just my experience, your mileage may vary.
