I shot the truglo bone collector smackdown .670 a few years ago in one of my 835's that I purpose built from a crown grade field gun. Highly polished (like a mirror) and deep cleaned 24" barrel, had a trigger job done that now allows approx a 3.5-4 pound, very crisp break, mounted a thumbhole stock with a sims pad and added a camo neoprene piece to the cheek area and of course optics. I have tried a TON of chokes and load combos through the 835 ever since my first one of seven now back in 1993. This particular gun has taken birds heads off inside of 20 (WITHOUT shooting longbeards). The smackdown choke will NEVER leave this gun. It quite literally seems to shoot everything I have fed it very well to ridiculously well. From the old Federal grand slam, Winchester and Remington premier lead loads to federal heavyweights. This choke just flat out shoots for my 835 (and every other 835 I've tried it in). 350 avg with hevi 7s, 300+ with hevi 6s, 275+ avg with the HW 7s and 160 avg with Fed lead 6s. It's a "long" choke with a nice smooth transition from the constriction to parallel portion and the porting is actually set into a slightly widened portion of the muzzle of the choke, similar to an artillery piece muzzle break. It doesn't appear to interfere with ANY wad, especially the flight contol wads but the porting does seem to do its job in reducing muzzle jump. As far as recoil reduction, I don't know. The way my gun is set up it is a dream to shoot the "roman candles" compared to any other 3.5" capable shotgun I have ever fired.