I've never understood why people think a shorter bbl will affect the spin of bullets versus a longer bbl. Maybe one of those super shorty pistols where the point of the bullet is past the muzzle, but in something like 10" plus? With a 1 in 9" twist rate, the bullet has already made one complete revolution by the time it hits the muzzle. Unless you have a poorly fitting bore to bullet, the bullet engraves and engages the rifling immediately, it doesn't "skid" straight down the bore for 11 inches before sudenly "catching" the rifling and starts to spin. Shorter bbls can even be more accurate than longer ones, the shorter bbl whips around less when fired. You lose range due to lower velocity and greater drop, but with less bbl harmonics to deal with the shot to shot consistency is there.