Search:

re muka's comment. 7mm08 at 16.5" gave 2500 with 140gr, my 20" 358win give's 2450 with 225gr. And that's loaded 1 gr under book max. both are based on the same cartridge.
As he suggests if you want...

just remember that a short barrel also kicks more and is louder. OK if you are running a silencer. if not I would be leaving a little more length in the barrel.
I had a short 243 when I had a...