In any case, from a physics standpoint porting has no meaningful effect -- it's all psychological and doesn't really help reduce anything except the number of people who will be willing to buy your shotgun should you ever decide to sell it. Most people who love porting feel that way simply because they like the obnoxious extra "BOOM," and the attention it brings. Do you remember the kid back in high school who put a Thrush muffler on his 2-barrel Gran Torino and flipped over the air cleaner lid? Same thing.
The True Believers, of course, will hammer me for telling you the truth.
I don'tknow if porting helps with muzzle jump or recoil in a shotgun, but I do know from personal experience that it works in pistols. I had two S & W Model 29's, one sent to Magna port and the other unported, same barrel length, at least 40% reduction in recoil and muzzle jump. I think it would be necessary to have identical shotguns one ported, the other not to make any valid comparisons or conclusions...as far as the noise aspect...just touch off a ported .378 Weatherby one time to know the true answer to that question....
It sure helps on my T/C Contender .44 Mag Barrel. Had the same setup before with no porting and it was a handful. As for the shotguns, my sons BT99 is ported and felt no different than the unported BT100 of mine. Results may vary but i say if recoil reduction is your goal, get your gun fitted to you. If that doesn't help enough, go with one of the many stock style recoil reducers(PFS, RAD, Gracoil, etc.).
<blockquote><I>"Most people who love porting feel that way simply because they like the obnoxious extra "BOOM," and the attention it brings."</I></blockquote>They're GUNS for crissake! They make LOUD noises when you pull the trigger.
Upgrade your ear protection and stop whining like a 5 year old who can't get his own way... or switch to archery!!
Sarge, I have a 300 win mag built by Bob Hart also, If you don't know if a muzzle brake works for sure, just take it off for the next shot. You will then be a believer. As far as porting for trap loads, not a noticable diff. Mike
Before a forcing cone is lengthened with a reamer it looks like a dark ring in front of the chamber, similar in size to a mans wedding band ring. When extended it will be wider, usually about one inch in width. Most of the time it will be dark in color, but on occasion it will be highly polished. HMB
I had a ported barrel that I tested to see if the porting made a difference. I made an aluminum sleeve that snugly slid onto the barrel. I cut a slot, the length of the sleeve, as wide as the rib, so I could slide it on inorder to cover the porting. Well with the sleeve in place I took the first shot. That was the end of the experiment, The sleeve after the first shot was on the ground under the barrel. It was no longer in the shape of a tube, the pressure from the first shot blew it off the barrel and nearly completely flattened it. There is a lot of pressure coming out of those ports and in my opinion it reduces muzzle rise, or at least gets the barrel back in position for the second shot in doubles. HMB
It has a lot to do with how much of the recoil of the gun is attributable to the powder and the expansion of the gases.
For shotguns, that's a very, very small percentage. Think of it, for a shotgun, the shot and the wad weigh upwards of 500 grains, while the powder is 20-ish. Ports can only redirect gases, so for a shotgun, porting is ineffective for recoil reduction because the percentage of recoil attributable to powder is so small.
For rifles and high powered handguns, the powder, and therefore the amount of recoil attributable to the powder and the expansion of the gases, can be a significant percentage of the overall recoil. So it stands to reason that porting, or muzzle brakes, can be very effective reducing recoil for high powered rifles or handguns.