.308 Winchester

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The .308 Winchester is a rifle round and is the commercial version of the military 7.62x51mm NATO centerfire cartridge. The .308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62x51mm NATO T65, Winchester Repeating Arms Company|Winchester (a subsidiary of Olin Corporation) branded the cartridge and introduced it to the commercial hunting market as the .308 Winchester. Winchester's Winchester Model 70|Model 70 and Winchester Rifle#Winchester Model 88|Model 88 rifles were subsequently chambered for the new cartridge. Since then, the .308 Winchester has become the most popular short-action big-game hunting cartridge worldwide.<ref name="about">Template:Cite web</ref> It is also commonly used for civilian target shooting, military sniper rifle|sniping, and police sharpshooting. The relatively short case makes the .308 Winchester especially well adapted for short action rifles.

Among calibers larger than 6mm, the .308 is by far the most popular short-action big-game cartridge among hunters worldwide.

From left to right .308 Winchester, .223 Remington, .44 Magnum, .45 ACP, 9mm Luger, and .22 LR cartridges. The 7.62x51mm NATO is similar in appearance to the .308 Winchester.

Cartridge dimensions

The .308 Winchester has 3.64 litre|ml (56.0 grain (measure)|grains) H₂O cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions.

Image:.308 Winchester.jpg|400px

.308 Winchester maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 = 20 degrees. The common rifling twist rate for this cartridge is 305 mm (1 in 12 in), 4 grooves, Ø lands = 7.62 mm, Ø grooves = 7.82 mm, land width = 4.47 mm and the Percussion cap| primer type is large rifle.

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) guidelines the .308 Winchester case can handle up to 415 MPa (60,190 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be Proof (firearms)| proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

The .308 Winchester and 7.62x51mm cartridges are not identical and there are minor differences in their inner case dimensions, though SAAMI does not list either cartridge as unsafe in a firearm designed for use with the other.<ref>Unsafe Arms and Ammunition Combinations technical data sheet at SAAMI</ref>

The .308 Winchester as a parent case

Several more cartridges have been developed using the .308 Winchester as a parent case, some becoming very popular for hunting, particularly in North America. These are the .243 Winchester, the .260 Remington (aka 6.5-08 A-Square), the 7mm-08 Remington, the .338 Federal, and the .358 Winchester (aka 8.8x51mm). In 1980, two rimmed cartridges based on the .308 Winchester were introduced for use in the Winchester Model 1894|Winchester Model 94 XTR Angle Eject rifle; the .307 Winchester and the .356 Winchester.