I have a good load for a 200 grain bullet using H 50 BMG. The velocity Is just shy of 3400 ft/sec in a 30" barrel. I use a drop tube to load with and went all the way up to 122 grains, but the best accuracy came from 117 grains and as I put more powder in the case velocity did not increase per grain after 118 grains but the muzzle flash was amazing because the cartridge could not burn all of the powder.
The best accuracy with this powder has been .091 thousandths with a 180 grain bullet and .108 thousandths with the 200 grain . My rifle did not shoot the bigger bullets as well so I stuck with the 200 grain. Here is the target I posted a while back on another post.