Modern version of the old Paradox barrel concept; it has had its followers but I think the twist needs to be pretty slow so the high velocity projectile slamming into it wont strip the rifling yet get just enough spin to stabilize better than out of a smoothbore. This means combining the twist, fit, velocity, and projectile length and weight to work together just so. I have one 12ga. smoothbore pump (cyl. bore) that has shot Win. Foster slug loads into 3" groups at 50yd. with nothing more than a bead front, bet it would do a bit better with a peep, Red Dot or scope. The way it kicks I might not be able to do better and dont know how much better that screw in would make it either. Probably not enough to matter in my world.
That said, if I had a barrel that could take interchangable chokes I would probably like to try one out because Im just that way (inquiring mind), but they are kinda expensive. Worst case would be Id find out the silly thing works terrific but only with very expensive sabot loads (this is the same reason I dont try Eley 10X in my 22's).
