Hi,

I want to put together a mk 12 spr rifle. I know that the 1/7 is the correct mil spec twist rate, but the uppers with that rate are currently backordered. As a practical matter, how much of a difference would it make to go with a 1/8 twist Douglas barrel? To be honest, I don't know how much mk 262 77 grain ammo I'll be shooting due to cost. I'll probably be using a fair amount of 55 grain range ammo. How much worse would the performance be?

thanks.