Hey guys. I have an Sig Cross and waiting for a new comp profile 308 barrel from Straight Jacket Armory. I am building a steady hunting rifle. I say that because length plays into the equation but weight does not. So the barrel will be 18” long. I have a young son who shot that rifle last deer season in Federal 6.5 creed amd he did well with it. I was wondering, how slow can I safely shoot 308 ammo. I know he won’t shoot over 250 yards and would like to find something lower recoil for him. Looking at MV only, 2,300fps works all the way out to 400 yards.