My bull barreled AR-15 likes IMI M855 rounds. I chronographed some and they are averaging 3075 fps out of a 1 in 8", 22" bull barrel. I can't find any load data that will push a 62 grain bullet that fast. The most accurate with Varget was 22.7 grains, 24 was listed as max load. 22.7 gave me about 2700 fps, and comparable groups. I would really like the extra 375 fps with the .5 inch groups. Besides Varget, I have BLC-2 and Benchmark powders. Any ideas?