...because I believe ....I feel it may ....seem to be .... any scientific evidence which proves the theory ...
For a serious competitor any mod that "seems", he "believes", or he "feels" enhances performance is a good idea. Whether it's been proven is secondary to what it contributes to the supreme confidence that is so helpful to winning.
FWIW, a theory is just a theory. There may be evidence to support it, but if it hasn't been proven and widely accepted as fact, it's still a theory. Seems intuitive that any scientifically proven improvements to shotgun barrel configuration would be embraced my the makers and users and quickly become SOP. There is ample reading to suggest those barrel mods are an improvement. Most of it is written by people wishing to sell you those mods. You'll have to dig harder to find evidence they don't work. You can't prove a negative...absence of evidence is not evidence of absence. In short, it's not scientific evidence, but acceptance in the public realm that will convince people (or not) of their worth. Browning has been at the forefront of providing competitors with what they thought they needed but, more important, what they wanted. It surely didn't hurt their sales temporarily to increase bore diameters from .729 to .745, lengthen forcing cones and port the muzzles.
Somehow, the 500 yr old maker, Beretta, didn't get the memo. They reluctantly enlarged the bore from .721 to a whopping .733 and called it the "optima bore." Otherwise, they seem to have ridden out the fashion wave for the last 20 years as I've never seen a factory ported Beretta O/U. Meanwhile, many shooters now consider ported barrels to be an absolute deal breaker on a used gun.
I "believe" longer cones than those of 80 years ago are useful for alleviating some of the very slight concern I have for shooting modern factory shells with plastic wads in my Foxes. Anyway, I "feel" it can't hurt and 3 of my Foxes that shoot thousands of modern target loads per year have lengthened cones. Two of my Foxes are bird guns and part of the appeal is shooting and hunting only with factory paper shells loaded with fiber wads in the 1950's. They have the original short cones.
