I'm not a fan of ported choke tubes and here is why. The ports on the choke will lessen recoil, but very minimally. The port will also does separate the wad from the shot, but this can also be done before it reaches the area of where the ports would be. The downsides, port will slightly hurt your long range pattern. An extended choke tube will not have any interference with the shot, like the extended ported choke will. Also, with a small amount of muzzel blast going out through the ports, shot velocity will decrease. And if the wad is slowed down too much, and separates from the shot enough it'll result in deformation of pattern again.
Correct me if I'm wrong, but this is the way I see it. I've talked to choke designers, and have been told, they make ported chokes not for performance, but looks, and that's what a lot of the customers will buy on.
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