On 1 July 1925, the U.S. Army began using the current naming convention where the "M" is the designation for "Model" and the number represents the sequential development of equipment and weapons.

Prior to World War II, the U.S. Army Ordnance Department received reports that the full-size M1 rifle was too heavy and cumbersome for most support troops (staff, artillerymen, radiomen, etc.)

During pre-war and early war field exercises, it was found that the M1 Garand impeded these soldiers' mobility, as a slung rifle would frequently catch on brush or hit the back of the helmet and tilt it over the eyes.

Many soldiers found the rifle slid off the shoulder unless slung diagonally across the back, where it prevented the wearing of standard field packs and haversacks.

[14] Additionally, Germany's use of glider-borne and paratrooper forces to launch surprise blitzkrieg attacks behind the front lines generated a request for a new compact infantry weapon to equip support troops.

[15][16] This request called for a compact, lightweight defensive weapon with greater range, accuracy and firepower than a handgun, while weighing half as much as the Thompson submachine gun or the M1 rifle.

[15] The U.S. Army decided that a carbine-type weapon would adequately fulfill all of these requirements, and specified that the new arm should weigh no more than 5 pounds (2.3 kg) and have an effective range of 300 yards (270 m).

[19] In 1938, the chief of infantry requested that the ordnance department develop a "light rifle" or carbine, though the formal requirement for the weapon type was not approved until 1940.

After the Marine Corps' semi-automatic rifle trials in 1940, Browning's rear-locking tilting bolt design proved unreliable in sandy conditions.

As a result, Williams redesigned the G30M to incorporate a Garand-style rotating bolt and operating slide, retaining the short-stroke piston as the .30 M2 Winchester Military Rifle.

Major René Studler of ordnance believed the rifle design could be scaled down to a carbine which would weigh 4.5 to 4.75 lb (2.04 to 2.15 kg) and demanded a prototype as soon as possible.

[24] Instead, the carbine falls somewhere between the submachine gun and assault rifle and could be called a precursor of the personal defense weapon since it fulfilled a similar role.

[26] Some failures to fire were reported in early lots of .30 caliber Carbine ammunition, attributed to moisture ingress of the non-corrosive primer compound.

[37] With the exception of T23 hiders mounted on M3 carbines, few if any T23 flash-hider attachments saw service during the war, though unit armorers occasionally hand-built improvised compensator-flash-hiders of their own design.

[37][26] Combat tests of the M2 carbine resulted in an Army Ground Forces request that led to development of the T13 recoil check adopted September 1945.

The largest producer was the Inland division of General Motors, but many others were made by contractors as diverse as IBM, the Underwood Typewriter Company, and Rock-Ola Manufacturing Corporation.

[citation needed] The M1 carbine with its reduced-power .30 cartridge was not originally intended to serve as a primary weapon for combat infantrymen, nor was it comparable to more powerful assault rifles developed late in the war.

[42] The M1 carbine gained generally high praise for its small size, light weight and firepower, especially by those troops who were unable to use a full-size rifle as their primary weapon.

[27][43] However, its reputation in front-line combat was mixed and negative reports began to surface with airborne operations in Sicily in 1943,[44] and increased during the fall and winter of 1944.

[45] In the Asiatic-Pacific Theater, soldiers and guerrilla forces operating in heavy jungle with only occasional enemy contact praised the carbine for its small size, light weight, and firepower.

[46] However, soldiers and marines engaged in frequent daily firefights (particularly those serving in the Philippines) found the weapon to have insufficient penetration and stopping power.

For the first time, U.S. soldiers had a weapon that allowed them to visually detect Japanese infiltrating into American lines at night, even during complete darkness.

However, in Korea, all versions of the carbine soon acquired a widespread reputation for jamming in extremely cold weather,[53][52][54] this being eventually traced to weak return springs, freezing of parts due to overly viscous lubricants and inadequate cartridge recoil impulse as the result of subzero temperatures.

[55][56] There were also many complaints from individual soldiers that the carbine bullets failed to stop heavily clothed[57][56][58][59] or gear-laden[60][59][61] North Korean and Chinese (PVA) troops even at close range and after multiple hits.

[9] "While the carbine's lighter weight and high rate of fire made it an excellent weapon for small-statured Asians, these guns lacked sufficient hitting power and penetration, and they were eventually outclassed by the AK-47 assault rifle.

Elements of the New People's Army and Islamic secessionist movements value the carbine as a lightweight weapon and preferred choice for mountain and ambush operations.

The M1 and M2 carbines were widely used by military, police, and security forces and their opponents during the many guerrilla and civil wars throughout Latin America until the 1990s, when they were mostly replaced by more modern designs.

[118] M1A1 carbines were made by Inland, a division of General Motors and originally came with the early "L" nonadjustable sight and barrel band without bayonet lug.

He found that many troops complained on the lack of effective range of the gun, which allowed the enemy to get close enough to throw hand grenades.

The AOM110 and AOM120 models (no longer produced) featured birch stocks and handguards, Parkerized receivers, flip-style rear sights and barrel bands without bayonet lugs.