I've reloaded 300 Blk for a while and I shoot the 125 SST in my 16" barrel AR. I do not have my load data in front of me at the moment but I run L'il Gun in mine. H110 and W296 are the same powder just rebranded and both have a faster burn rate than L'il Gun so you may pick up a little more velocity with the slower burn. My son has taken NC deer from a 180# 8pt at 20 yards to a 153# doe at a ranged 176 yards and the SST has performed fantastic with good internal damage and a golf ball size exit on every animal taken. I run L'il Gun in my 16" bolt gun behind the Barnes 110 Tac-tx and save the 110 - 296 for the 44 mag.