Re: info needed on smokless build
I'm using a 1:22 twist, 26" PacNor. I wish the contour were a bit lighter, the thing shoots lights out but is quite heavy.
You can go faster with the twist, but last I followed development there really aren't any bullets out there (despite development efforts) with higher BC than what we have now, requiring 1:20 or faster.
What do you plan to use for your priming system? I do not recommend you use the plug style which uses shortened cases in the existing bolt. They are prone to gas-cutting the nipple that the case presses onto when forces against the plug by the bolt. Once that happens -- and it doesn't take much -- your $80 plug is shot. I've been there, and converted to a newer 209 system.