The short answer is yes.  Civilians are permitted to own "silencers" in 39 U.S. states.  However, they are strictly controlled and tracked by the BATFE.  Sliceners have been deemed by the BATFE as an NFA item.  You can read more about NFA items here. more »

This article provides information on the USC/UMP conversion. I am here to tell you everything you need to know about it. more »