has anyone used a mossberg replacement barrel for a rem 870. i am interested in their fully rifled cantilever barrel but i was concerned with the porting at the muzzle. in turkey guns the porting slows the wad and separates it from the shot resulting in better patterns. i wondered if the porting would have a negative or positive effect on saboted round. i'm not sure if sabots are designed to stay with the bullet or separate once they leave the muzzle. can anyone clarify this for me. Thanks Zack