Originally Posted by Bowshooter52ga
From what I understand, you don't need or want to use a rifled barrel with FSRs as they have the fins that cause the round to spin in flight. From what I've been told rifling in the barrel can actually counteract, or disturb the spin the fins impart on the fsr.
This is true and not true at the same time. It depends on the rifling inside of the barrel as well as the bore size of the barrel and round.
My old Armson rifled barrel would be terrible with FSR rounds, but mainly because it is rifled the wrong direction. Your regular RAP4 Rifled barrels have straight 'rifling' (if you can even call if 'rifling').
When your are talking about the physics of paint, normally your typical rifle/firearm physics don't apply. In the case of the FSR round a lot of the factors that didn't apply now do, such as the depth and angle of the rifling.
So the key to your FS rifled barrel will be a good bore fit combined with rifling that isn't too aggressive or too subtle.