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 imperial unit and customary unit equivalent, and was most commonly used for indicating a class of full-power military main battle rifle (MBR) cartridges. The measurement equals 0.30 inches or three decimal lines, written .3″ and read as three-line. 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 , although Soviet weapons commonly use a bullet, as do older British (.303 British) and Japanese (7.7×58mm Arisaka) cartridges. Pistol cartridges in 7.62 mm caliber Many pistol cartridges are in this caliber; the most common are: 7.62×25mm Tokarev, also known as 7.62 mm TT, is used in the Tokarev pistol, and many of the World War II Soviet submachine guns 7.63×25mm Mauser, which was the basis for, and has nearly identical dimensions to, the Tokarev, but has different loading specifications. 7.65×25mm Borchardt, from which both the Mauser and Parabellum cartridges were developed 7.65×21mm Parabellum 7.65×17mm Browning, also known as .32 ACP 7.62mm SP-2, used only in the TKB-506 cigar cutter pistol Revolver cartridges in 7.62 mm caliber Some of the revolver cartridges in this caliber are: 7.62×38mmR is used only in the Nagant M1895 revolver. .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