I've been reading here and there about barrel porting and lengthen the forcing cone. It is supposed to improve the pattern. Did anyone did it, did you see any real difference ?
I purchased a Mossberg model 500 at Wal-Mart for $257, which had a factory ported 28" barrel. In comparison to my 28" 870 and 28" BPS, both of which are heavier than the 28" 500, I believe that I detect less muzzle rise after the shot when using the 500.
I've gotten some impressive patterns through the Model 500, with #7.5 Lead loads through the factory Improved Cylinder, and the factory Full chokes at 30 yards. A .675 Undertaker Non-Ported choke shot really tight patterns with #7.5 Lead from 20-25-30 yards. A .690 Primo's Dead Deer choke did very well with 00 Buck at 35 yards.
Well ports. Ok they do take muzzle jump out of a gun. They will take felt recoil out. Now would I spend the money to do it. No
Forcing cone work. Now alot to be found in the chamber and forcing cone of a gun. You can reduce felt recoil with a long forcing cone. You can get a better pattern. It will be a more even pattern 95% of the time. Look at it like this. If you have a 5 foot wall to get up. You had a 10 ft a 20 ft and a 30 ft long walk board to go up. What one would you take and why? Now would I spend the money to do forcing cone work? Yes.
Now with that said alot of times if you change one thing it will effect something else. You sometimes will need a choke change if you do forcing cone work. Find you someone that will work on the gun and help you tune it to the shell you want.
The one thing which I've learned in a lifetime of messing with shotguns is that there are few "fixes or modifications" which apply equally to all shotguns. I'm personally not a big fan of barrel porting due to the increased decibel levels and nominal reduction in barrel rise. Forcing cone work by a competent gunsmith is a whole new ball game depending on the shotgun. Most SBE I's greatly benefit w/ forcing cone lengthening and polishing w/ better more even patterns w/ reduced recoil. The "newer" Remington shotguns esp. the less expensive Express 870's, seem to improve greatly w/ forcing cone work and barrel polishing. Most "overbored" shotguns ie. 835 and BPS don't benefit as greatly from lengthening and polishing of the forcing cone, but as I said all shotguns are different.