The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rimless, bottlenecked, centerfire rifle cartridge. It is a standard for small arms among NATO countries.
First developed in the 1940s, the cartridge had first been introduced in U.S. service in 1954 for the M14 rifle and M60 machine gun.
A sniper rifle is a high-precision, long-range rifle. Requirements include high accuracy, reliability, mobility, concealment, and optics, for anti-personnel, anti-materiel and surveillance uses by military snipers. The modern sniper rifle is a portable shoulder-fired rifle with either a bolt action or semi-automatic action, fitted with a telescopic sight for extreme accuracy and chambered for a high-ballistic performance centerfire cartridge.