I have a sps varmint that has not been shot. I dont like the the 26" length for hunting so I want to cut barrel down. I mainly shoot 168gr and 165gr bullets. With the 1/12 twist what is the least that I should cut barrel down? I do some long range shooting but 800yds is the max. I am building this rifle for hunting plus paper punching. Would I be better off, buying a new barrel with 1/11 or 1/10 twist? Any help would be appreciated! Thanks