A few days later a box from Briley showed up. The Diffusion chokes are gently rifled, the idea being to spin the wad and disperse shot more quickly, giving you a quick-opening pattern for close range targets. It’s similar to the Paradox guns of the British Empire, which were rifled at the muzzle so they could shoot either a bullet or shot. Fabarm used to make an O/U with fixed rifled chokes specifically for European woodcock hunters and, for the extremely well-heeled, Holland & Holland makes a few paradox guns today. Incidentally, Briley also made (or maybe still makes) straight-rifled turkey chokes that were supposed to stabilize the wad for tighter patterns. Whether they stabilized wads or not I don’t know, but they sure worked well. But I digress.