When you get right down to it 99% of shooters can not tell or take advantage of anything that changes shotgun performance by ten percent plus or minus on a consistent basis. It is all marketing hype to me. Just to many variables in shotgun shooting. Just change shells or just shot size and it changes, same for distance, tempature, clothing worn, and everything else involved. Perhaps you might lower the odds slightly but equipment is just another variable to me.
Becker use to be a guru for Fox shooters with his custom boring, choking and general tweaking of guns for the well to do. Now days a guru would go for over bored ported barrels with 4" forcing cones and custom screwing choke tubes. The US norm 12 bore is now over bored to most people.
Just like golf makers make a thousand different standard variations of clubs gun maker will make anything which will sell or stimulate sales. Meeting market demands keep them gong and if some writer convinced us that 12 should all be bird 13-14 ga and buyers demanded them all makers would be making under bored guns today.
