I have a 22 br varmint rig with a .246 neck Krieger barrel on a savage action with the nut removed. My rifle shoots most powders pretty good but it seems to really like N-135 and AA 2520 the best. I have tried varget, benchmark, 2230, 2460 and 10x. N-135 just shoots better groups with about any charge I put in it. I have noticed that my br kind of likes all powders on the warm side before it wants to put the groups together. currently I'm loading 31.2 grains of N-135 with 52-53 grain bullets. You can go to about 32.8 gr of AA 2520 with 52-53 grain bullets, but always start a few grains lower and work your way up. There's a lot of variance between powder batches.