Trying to figure out a new load. 123 SST and AR-comp

[1Shot]

Any change in a load can effect accuracy. I tried factory Hornady 123 SST ammo and handloads using IMR 8208, CFE 223, H 335 and IMR 4895 using different primers, COAL, and I just could not get the 123 SST to shoot under 1 1/2" out of both of my rifles. One has a BCA and the other Oden Works barrels. Both will shoot sub MOA with 120 Sierra PH and Speer GD with IMR 8208.