IMR 2064 powder produces sub MOA in both my 8MM mauser rifles.
In my hunting 8mm, I use the 175 Sierra as well as the 170 Hornady RN, for whitetails, with excellent results. The Sierra is chronographed from my 20" barrel @ 2700fps and the Hornady RN a bit slower at 2650fps.
Its THE only powder I will use for this caliber!!
CW