The XM148 was an experimental 40 mm grenade launcher developed by Colt Firearms as the CGL-4 (Colt Grenade Launcher). Colt manufactured the launcher for field testing during the Vietnam War era.

However, the term "CAR-15" is most commonly associated with the Colt Commando (AKA: XM177); these select-fire carbines have ultrashort 10.5-inch (270 mm) and 11.5-inch (290 mm) barrels with over-sized flash suppressors.

Jul 8, 2021 · Some time just after issue of the SMGs the designation XM177E1 was applied, so there never actually was a XM177, but could be retroactively applied the CAR-15 SMG tested in 1965. The after action assessment is long and detailed, but we’ll just skip to the durability/reliability assessment.

The increased length reduced noise and muzzle flash, and allowed fitting of the Colt XM148 grenade launcher. A metal boss was added to the moderator for mounting of the XM148 and rifle grenades. The chambers were chrome-plated.

Jun 1, 2020 · The increased length reduced noise and muzzle flash, and allowed fitting of the Colt XM148 grenade launcher. A metal boss was added to the moderator for mounting of the XM148 and rifle grenades. The chambers were also chrome-plated.

Jan 24, 2019 · To address these issues, Colt developed the CAR-15s final version, the XM177E2, dubbed by Colt the Model 629.

Feb 15, 2019 · The Colt CAR-15 Commando (XM177) was an assault carbine developed during the United States military involvement in the Vietnam War (1955-1975) to fulfill a need for a portable, close-in weapon system for use by special forces operating in the jungle.

The XM177 uses a unique flash suppressor sometimes called a flash or sound moderator for its 10-inch (250 mm) barrel. This device is 4.2 inches (110 mm) long and was designed primarily as a counterbalance measure as the shorter barrel makes the weapon unwieldy.

The CAR-15 XM177 or CAR-15 Commando was a part of the CAR-15 Military Weapons System designed in 1966 in response to the US military's desire for a compact M16 variant to improve on the inadequacies of earlier shortened M16 types.

Mar 1, 2010 · The XM148 was a revolutionary weapon that allowed infantry soldiers to engage the enemy beyond the range of hand grenades without the weight and complexity of light mortars.