Originally Posted by Havoc-paintballer
A freak barrel and a bored barrel are going to shoot the same since the ball is only touching the insert in either case.
SO not true. The ball is still accelerating after the insert, and the size of that bore along with the degree of porting is a big factor in extra velocity (which translates to air efficiency on most guns). And, once some paint breaks in that barrel, different sized step bores will act differently in terms of shooting through breaks... both of these are clear and observable factors in barrel performance.