I don't think anyone has touched on the "mental factor" of shotgun porting. This plays a important part in shotgun shooting.
If the shooter BELIVES something will improve his shooting, it will.
Go to any large clay target shoot and look at what people are useing on their guns. You will see everything from different colored beads and ported choke tubes to trigger shoes and recoil pads mounted upside down. They work for the people useing them because they believe they work.
If the guy that won the Grand American Handicap had a 9/16" nut welded on the end of his gun, you can bet that the next week there would be a lot of guns with nuts welded on them.
