The 7.62 mm caliber is a nominal caliber used for a number of different cartridges. Historically, this class of cartridge was commonly known as .30 caliber, the equivalent in Imperial and United States Customary measures. It is most commonly used in hunting cartridges. The measurement equals 0.30 inches or three decimal lines, written .3″ and read as three-line.[1]
The 7.62 mm designation refers to the internal diameter of the barrel at the lands (the raised helical ridges in rifled gun barrels). The actual bullet caliber is often 7.82 mm (0.308 in), although Soviet weapons commonly use a 7.91 mm (0.311 in) bullet, as do older British (.303 British) and Japanese (7.7×58mm Arisaka) cartridges.
.32 Long Colt – originally chambered for small-frame Colt revolvers and the Marlin model 1892 rifle, this cartridge uses a heeled bullet with a case the same diameter as the major diameter of the bullet. It shares dimensions with the .32 rimfire cartridge of the same length. It is not to be confused with the .32 Colt's New Police cartridge.
.32 S&W Long is also known as .32 Colt's New Police when chambered in Colt revolvers. The original loading for this cartridge used a round nose, or flattened round nose (in the case of the .32 Colt's N.P.) and was chambered widely in revolvers made in the US and Europe through World War II. This cartridge is used in several modern target pistols (not revolvers) with flush-seated wadcutters. The short version of this cartridge (.32 S&W) was chambered in many break-top revolvers at the end of the 19th and beginning of the 20th centuries in the US and Europe.
.32 H&R Magnum is the only revolver cartridge in this caliber in wide use today, mostly in small-frame revolvers. This is an extended version of the much earlier .32 S&W Long, which is an extended version of the .32 S&W.
.327 Federal Magnum is a new cartridge developed jointly by Ruger and Federal. This cartridge is an extended version of the .32 H&R Magnum.
7.62×45mm vz. 52, made solely for the Czechoslovakian vz. 52 rifle, was replaced by 7.62×39mm.
7.62×51mm NATO and its civilian variant .308 Winchester, sometimes described as .308 NATO by people mixing Imperial and Customary measurements, is used by some civilians, with metric measurements used by NATO.
7.62×53mmR, Finnish design based on the Russian 7.62×54mmR round.
7.62×54mmR, another Russian cartridge, it was first used in the Mosin–Nagant rifle in 1891. The modern versions of the cartridges are now in wide use in numerous world armies as sniper rifles (particularly the SVD family) and machine guns (numerous types, many developed from AK family, such as the PKM).
.30-06 Springfield, is a US military cartridge used in World War I, World War II, the Korean War, and the Vietnam War, as well as hunting game, is known as the 7.62×63mm in metric measurement.
