The 7.62×51mm NATO is a rimless, bottlenecked, centerfire rifle cartridge. It is a standard for small arms among members of the North Atlantic Treaty Organisation.
Unfired 7.62×51mm NATO round (B) next to three recovered bullets, showing rifling marks (A)
.50 BMG, .300 Winchester Magnum, .308 Winchester, 7.62×39mm, 5.56 NATO, and .22 LR
Service rifle cartridges loaded with projectiles: (left to right) 7.62×54mmR, 7.62×51mm NATO, 7.62×39mm, 5.56×45mm NATO, 5.45×39mm
7.62×51mm NATO cartridge case ejection from a British L129A1 Sharpshooter Rifle after firing L59A1 "High Performance" ammunition featuring a 10 g (155 gr) bullet
The 5.56×45mm NATO is a rimless bottlenecked centerfire intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, and SS111 cartridges. On 28
7.62×51mm NATO
…First developed in the 1940s, the cartridge was introduced in U.S. service in 1954 for the M14 rifle and M60 machine gun. The later adoption of the 5.56×45mm NATO intermediate cartridge and assault rifles as standard infantry weapon systems by NATO militaries started a trend to phase out the 7.62×51mm NATO in…
5.56×45mm NATO with measurement, left to right: Bullet, case, and complete cartridge
The 7.62×51mm NATO and 5.56×45mm NATO cartridges compared to an AA battery
Service rifle cartridge cases: (left to right) 7.62×54mmR, 7.62×51mm NATO, 7.62×39mm, 5.56×45mm NATO, 5.45×39mm
5.56×45mm NATO cartridges in a STANAG magazine