COLT TROOPER PATROL M4 CARBINE 5.56X45 NATO SEMI-AUTO RIFLE Colt continues to expand on its legendary M4 platform, which has been duty-tested by the world's most elite Military and Law Enforcement agencies, with the introduction of the new Colt TrooperA(R) Patrol Carbine. The TrooperA(R), based on the class-leading LE6920, offers customers another great point of entry into the world of duty-grade Colt AR-15A(R) carbines. The TrooperA(R) Patrol Carbine is offered in 5.56 x 45 NATO, and features a 16.1" barrel and a 13" M-LOKA(R) capable Centurion Arms forend with a Picatinny rail at 12 o'clock, and M-LOKA(R) mounting slots at 3, 6 Mfg: Colt