chopper stopper
n.— «He was one of about two dozen men arrested in 2004 in Operation Chopper Stopper, a multi-agency investigation named for street slang for assault rifles.» —“Woman ran city drug ring they broke up, police say” by Paul Pinkham, Jim Schoettler Times-Union (Jacksonville, Florida) Dec. 26, 2006. (source: Double-Tongued Dictionary)