If you take a close look at the barrel, when its fired. Its biggest bend IMO, happens at the end of the forend. Then follows down the barrel like a wave in the water. The porting could not have caused a bend in the barrel at that point. The bend is normal in a barrel that long with no fixed rib to add strength and/or rigidity to the barrel. Like you would find with two barrels and a rib soldered to each other.
Porting does reduce muzzle jump to a small degree. I myself, have never really noticed the shooter next to me that had ported barrels or not!!! I was always to busy focusing on my shot, to worry if his ported barrels were blowing crap at me or making more noise!!! How much ported barrels helps, has never been measured to my knowledge. Of course reduced muzzle jump only really helps when your shooting a true pair of shots. Which of course is only shot by a small number of trap shooters. Even before the crash of 08. Our club had about 60 shooters for the singles event. then about 35 or so for handicap event. Only about 12 or so showed up for doubles every month. I expect this number should be higher at large shoots. Roughly 1 in 6 shooters is not many shooters that shoot doubles. So why have your barrels ported is a very common belief in Trap. Since most shooters only shoot a single shot for the most part. If you look at Bunker Trap shooters, they have lots of extra porting holes when compared to the pattern on any Browning strait from the factory. Brownings shotgun barrels are much lighter in weight when compared to a P-guns heavy barrel or a K-80 barrel. These heavier barrels naturally help reduce muzzle jump. Which is fine if you can afford a 13 thousand dollar shotgun.
I have talked to several shooters over the years who swear that the combination of ported barrels and over-bored barrels helps reduce felt recoil in their shotgun after having the work done by a vendor. After having the work done and shooting 200 or 300 rounds in one day, that evening or the following morning they said their shoulder did not bother them anymore. Did they sub-consciously justify the reduced recoil in their head? Does having this work done, work for everyone. I think not. I think it can help certain shooters. I do know the mind can do extraordinary things if you really believe. Bottom Line, would I pay a vendor to have this work done to my barrel? I would say NO!!! I have ported barrels in both my 525 and my BT-100. They both work extremely well. Muzzle jump is not a issue for me. Cleaning the ported barrels is a zero issue for me. I just wipe down the barrel before I place it in the gun case. To remove any grease and my body's oils from the gun. After I get home I wipe the metal down with a rem-oil wipe. Run a Tico-Tool down the barrel a few times, I'm good to go!!! No Rust, No Plastic Build-up!!! So in closing save your money, and just buy more ammo and targets. Don't worry about the guy shooting next to you. Just focus on your next target. break em all Jeff