Okay got a question and not sure where to find a correct answer. I hope one of you folks can point me the right way or maybe even know. I have been reading at the BATFE site but all I have done is made a bigger mess in my mind. LOL I want to make a short barrel shotgun. I will follow the rules so it will be legal. Here is the thing, the gun I would like to use is one with 3 bbls, NEF 20g, .223, .243. Can I cut the shotgun bbl down and swap it back and forth on the frame as long as I do not have the pistol grip on the frame with a rifle bbl? Or do I just need a different donor to make my SBS? Thanks for any help, David.