I'm shooting the 140 pro- hunter in my 7rem with either rl22 or I 4064. I was using 7828, but it got flighty in cold weather in my current 7 rem (the last two liked just fine). The 4064 was a whim as sierra shows it, and I needed to burn up a few # of 4064. It shoots well and produces 3100 fps at sierra's charge weight. With rl22, I'd run sierra's charges first, vbut you may need to go to a couple of grains higher as lyman's 49th and hodgdon #26 suggest. They top at 70 grains rl22 with a 140.I want to try some 140 gr sierra gamekings in my 7 rem mag. I got some federal brass as a gift. my gun is a custom with a 26" shilen barrel . where should I start?
any advice would help since I'm new.
thanks