AR-15 and M16 5.56mm automatic rifles "made Colt the small-arms sensation of modern warfare". Their unmatched accuracy, performance and durability are available in their direct descendent, the Colt semiautomatic-only, sporting rifles. They're ideal for hunting, plinking and competition shooting. This Colt Pistol Flat-Top upper assembly comes complete with Matech adjustable flip-up rear sight, charging handle, bolt and bolt carrier assembly. Featuring a Picatinny-style Flattop, this upper is more than ready to offer the shooter maximum versatility when it comes to mounting optic devices. Unique to this upper, it features a free float monolithic rail. The free floated barrel reduces the chance of accuracy-reducing pressure on the barrel and the monolithic rail means the entire top of the handguard is machined together in conjunction with the upper receiver portion of the upper assembly. The monolithic rail presents the user with an extremely versatile single plane rail which eliminates the chance of front mounted accessories being canted or unlevel.