I gas check my .30 cal rifle boolits. A new Ruger American likes .310 while my warhorse Model Seven which has seen several thousand factory ball rounds needs a .311. I have yet to try powder coating in my rifles because the gas checked tumble lube boolits work so well. My 30-30 likes .310. I use NOE expander plugs to open the case mouths to accept the boolits nicely. 2400 is my go to powder for about 1675 fps.