I think the only advantage of extended tubes are, they are easily identified, and quick to change (no wrenches needed) I just don't know if they improve shot patterns by so called stripping the shot cup?
Jackmac, I have owned a couple of guns with ported barrels and now I own a K-80 with unported barrels. I cannot notice any difference. Save your money.
Corey, I really can say that I prefer the patterns my Briley chokes give in lieu of my standard Krieghoff chokes, but it is a personal choice. The other reason I choose extended chokes is I rest my barrel on my toe, therefore, if I have a mishap and it slips off of my toe and grinds on the concrete I only have to pay to replace my choke tube not a 4K barrel. Hope this helps.
The theory behind extended choke tubes is that the restriction is spread out over a longer area than with a flush mount. Example: going from bore diameter to say a modified choke at .020 restriction, the angle of the inside of the choke will be less on a choke tube that is 3 inches long and extends out of the barrel, than a flush mount tube that is only 1 1/2 inches long. In other words the tightening of the column, within which the payload of shot travels through, will be spread out over a further distance making the change more gradual. This is said to provide less shot deformation and provide a better overall pattern.
To address the question of porting and it's benefits, I have seen no difference in patterns on a patterning board or distance that the wad travels, from a ported vs. non-ported barrel.
To add to this discussion, I have also tried 8 fingered wads and numerous different 4 fingered wads, and on my range all the wads travel roughly the same difference, with some of the 4 fingered wads falling closer to the trap house than the 8 fingered wads. Due to this discovery and the fact that 4 fingered wads seem much easier to load, I have switched over exclusively to 4 fingered wads.
Gotta go with Big Tuna here-bought a set of ported Briley's for my Ultra sporter, never again. Hard to clean, LOUD, and no recoil reduction I could feel. Not a knock on Briley as I believe any brand would be the same.
The ones I have were made to order and are ported. The only thing I can see different is the wad does come off the shot a little quicker, The wad drops about 6-7 yards before the un-ported tubes I have.
In trap I am not sure if that 6 or 7 yards are that important but cleaning is no big thing. I just clean the barrel with the tube in it and they both clean up fine.
Wast of money ?? Mine cost no more either way ported or not.
I prefer unported tubes to ported. After stating this, all I use are Comp-N-Choke tubes. They don't, and won't, make a unported tube. The slots that are in their tubes are there to strip the wad away from the shot. As far as performance, Comp-N-Choke has them all beat hands down in the guns that I shoot. The downside for this performance is the cleaning that these tubes need on a regular basis. Just a little food for thought.