Norman74, I know that you can shoot slugs out of a Vang modified barrel. Slugs can be used in most any choke except extra full turkey chokes and other super full chokes. But my point was that if you have the Vang job done you have a fixed choke. Having the barrel threaded for screw in chokes allows the use of Rifled, extra full, full, trap, modified, improved modifed, improved cylinder, skeet, spreader, cylinder and many more specialty chokes. The screw in chokes give you fexibility. MIKE.