The .30 Carbine (7.62×33mm) is a rimless carbine/rifle cartridge used in the M1 carbine introduced in the 1940s. It is a light rifle round designed to be fired from the M1 carbine's 18-inch (458 mm) barrel. History Shortly before World War II, the U.S. Army started a "light rifle" project to provide support personnel and rear area units a weapon with more firepower and accuracy than the standard issue M1911A1 .45 ACP handgun and half the weight of the standard issue M1 Garand .30-06 rifle or the .45 ACP Thompson submachine gun. The .30 Carbine cartridge was developed by Winchester and is basically a rimless .30 caliber (7.62 mm) version of the much older .32 Winchester Self-Loading cartridge of 1906 introduced for the Winchester Model 1905 rifle. (The .30 Carbine's relatively straight case and round nose bullet have misled some to believe it was designed for use in pistols.) The .30 Carbine uses a lighter bullet (110 grain versus 165 grain) and improved powder. As a result, it has approximately 41% higher muzzle velocity with 27% more impact energy than the parent .32 WSL cartridge. At first, Winchester was tasked with developing the cartridge but did not submit a carbine design. Other firms and individual designers submitted several carbine designs, but most prototypes were either unreliable or grossly off the target weight of five pounds. Army Ordnance Major Rene Studler persuaded Winchester that the Winchester M2 .30-06 rifle, a design started by Ed Browning and perfected by Winchester engineers including Marshall "Carbine" Williams, could be scaled down for the .30 Carbine cartridge. The result was the M1 carbine. The M1 carbine was issued to infantry officers; machine gun, artillery and tank crews; paratroopers; and other line-of-communications personnel in lieu of the larger, heavier M1 Garand. The weapon was originally issued with a 15-round detachable magazine. The carbine and cartridge were not intended to serve as a primary infantry weapon, nor was it comparable to more powerful intermediate cartridges later developed for assault rifles. The M2 carbine was introduced late in World War II with a selective-fire switch allowing optional fully automatic fire at a rather high rate (850–900 rpm) and a 30-round magazine. The M1 and M2 carbines continued in service during the Korean War. A postwar U.S. Army evaluation reported that "[t]here are practically no data bearing on the accuracy of the carbine at ranges in excess of 50