I have never purchased or used a shotgun adapter before. I am looking into buying the 12 gauge adapter set for 400 bucks off gaugemate.com, it's called the pocket arsenal. It comes with 8 adapters and they are seven inches long and rifled. I'm very curious to hear if anyone here ever tried rifled shotgun adapters. If so leave some info and tips below because I don't want to lose 400 bucks on garbage.