I wouldn't even ask, but the whole time I was growing up my grandfather had a bullet trap in his basement for shooting pistols, and he lived in Oak Park in Kansas City. Granted that was a different time, and he was a Johnson County sheriff, so I don't know if he was doing it legally or just got away with it because he was a cop. He was very by the book, though, so I imagine it was legal for him at the time or I don't think he would have been doing it. He was the kind of cop who would (and did) give his own daughter a speeding ticket, so I doubt he would have been discharging a firearm in city limits if it weren't legal for him to do so. If anyone knows the legal requirements for having a bullet trap I would appreciate it. My plan if it's legally possible would be to build a little soundproof closet in my workshop, that way it wouldn't scare the neighbors.