United Defense M42

Marlin Firearms · Submachine Gun · Out Of Production · 1942

Also known as: UD M42, UD-42, Marlin UD M42, United Defense Model 42

Overview

The United Defense M42 is an American blowback-operated, select-fire submachine gun developed during World War II. Designed by Carl Swebilius around 1942 and manufactured by Marlin Firearms for the United Defense Supply Corporation, it was chambered primarily in 9x19mm Parabellum and fired from an open bolt at roughly 700 rounds per minute. Although ordered originally for export, the bulk of the roughly 15,000 guns produced were issued to agents of the Office of Strategic Services for clandestine and partisan operations.

Specifications

Weight (empty)4100 g (144.6 oz)
Overall Length820 mm (32.28")
Barrel Length279 mm (10.98")
Action TypeBlowback
Firing MechanismOpen Bolt
Trigger TypeSingle Stage
Magazine Capacity20 rounds
Magazine TypeDetachable Box
Muzzle Velocity335 m/s (1099 fps)
Effective Range100 m (109 yd)
Rate of Fire700 rpm
Barrel RiflingRight Hand
Frame MaterialSteel
Barrel MaterialSteel
Stock MaterialWood
FinishBlued

Calibers

Features

Service history

Operators

Conflicts

Production

Estimated total produced: 15,000 · Production years: 1942-1943

Approximately 15,000 manufactured by Marlin Firearms for the United Defense Supply Corporation.

Origin

Country of origin: United States

Designer: Carl Swebilius

Discontinued: 1943

Notes

Production was contracted to Marlin Firearms under the United Defense Supply Corporation, a US government procurement front. Magazines were commonly issued welded back-to-back in a 'jungle clip' for rapid reloads. A .45 ACP prototype was developed but never entered series production.

Background

Built for export but never delivered to its intended foreign buyers, the M42 found its true calling in the hands of OSS operatives and resistance fighters, who valued its smooth, finely machined action enough to favor it over the cruder mass-produced submachine guns of the era.