Original Item: Only One Available. This is very rare example of a U.S. WWII United Defense UD M42 display submachine gun, built from all original WWII issue parts on an original BATF compliant non-firing display receiver, making this a 100% legal display Sub-Machine gun. This receiver was created by using portions of the original torch cut receiver, including the barrel bushing, combined with some new made steel portions. It has properly had a 25% section of the total length completely replaced with solid steel bar stock. Meaning a 1/4 length section of the display receiver is solid steel, making this totally legal to own without a license of any kind. Every part on this display gun is original WWII manufacture other than 25% of the receiver replaced by solid steel (as required by BATF).

As far as we can tell, the barrel is still live, with no signs of attempts to deactivate it. It comes complete with an original magazine, which will be deactivated where required.

The United Defense M42, sometimes known as the "Marlin" for the company that did the actual manufacturing, was an American submachine gun designed and used during World War II. It was produced from 1942 to 1943 by United Defense Supply Corp. for possible issue as a replacement for the Thompson submachine gun and was used by agents of the Office of Strategic Services (OSS). However, its usage was limited, and the Thompson continued to see service until the end of the war, alongside the M3 submachine gun, which was designed around the same time as the M42.

The one area where it did see the most use was with resistance fighters in Europe, who received them from the OSS. France, Czechoslovakia, Belgium, the Netherlands, and other countries received the submachine guns, which were chambered in 9mm Luger Parabellum, which was readily available in Europe, as it was the same cartridge used by many other European pistol and submachine gun designs. It was also the same round used by the Sten machine guns that were also supplied to various resistance forces throughout Europe.

This is the first example that we have ever had, and it is in great shape, with the original finish well retained, and intact stocks that are still in very good condition. It still has the original manufacturing stamping on the left side of the trigger group / lower receiver:

UNITED DEFENSE SUPPLY CORP.
- - - NEW HAVEN, CONN. - - -
UD M.'42    PAT. APPLIED FOR

It is also marked on the rear right with 11348 and next to that on the bottom behind the trigger guard with 11564, both of which look like they could be the serial number based on production numbers. It may have been remarked at some point. There are additional production markings elsewhere on the gun.

It still retains both the front and rear sling swivels, as well as a functional rear sight, which is raised or lowered using the dial on the left side of the receiver. The trigger still pulls, though the selector currently does not move, and the magazine can be correctly removed from the magazine well.

A lovely example of a hard to find WWII Machine gun! Ready to add to your collection and display!

The UD M42 submachine gun was designed by Carl G. Swebilius of the High Standard Manufacturing Company in 1940. When High Standard was tasked with producing .50 Browning machine guns for the British government, further development of the submachine gun was handled the United Defense Supply Corporation founded by Pope and Jackson of the British Purchasing Commission. United Defense did not have any manufacturing capability so it contracted with Marlin Firearms to have the M42 actually built.

The UD M42 was promoted as a replacement for the Thompson submachine gun, which the U.S. military considered both expensive and complicated to produce. Early model Thompson drum magazines were heavy and made a rattling sound when soldiers moved around with the weapon. Made in both 9×19mm Parabellum and .45 ACP prototypes, the 9mm version was the only one to ever see widespread production. About 15,000 were produced in the last three years of World War II. Only six .45 ACP prototype test guns were made.

The weapon holds 25 9mm rounds in its magazine (designed by John E. Owsley, covered by patent 2,289,067). It has a cyclic rate of 700 rounds per minute. Frequently two 25-round magazines were welded face-to-face allowing a quick reload when the first became empty. However, just like using the Sten submachine gun, resistance fighters were instructed to fire in short bursts when firing in full automatic to reduce the risk of overworking the weapon that would cause jamming and overall keeping it in a good condition. They were also strongly advised to keep the double magazine clear of grass, mud, dirt and any other debris out because of the risk of jamming. The weapon itself weighs 10 lb (4.54 kg) when empty, with a length of 32.3 in (820 mm). The barrel length is 11 in (279 mm), and it has six-groove right-hand rifling.

An extremely simple design, it was a straight blowback, selective fire weapon. It was built under "hurry-up" war conditions and some of its design flaws stem from this approach. Problems with the weapon were varied. Under combat conditions it was found that the sheet metal magazines had a tendency to warp out of shape causing feeding problems. They had little tolerance for exposure to large amounts of mud and sand and tended to jam if not cleaned regularly. The gun was also labor-intensive to produce. It used all machined parts, no stampings, and under wartime conditions, machine work is at a premium. However, proving ground tests showed it was easier to field strip and maintain than the Thompson or Sten Mark II and was more accurate at 100 yards. Despite its expense and precision, the UD M42 enjoyed a good reputation in OSS and resistance usage.

The War Department was interested in purchasing large quantities of the M42, but due to complicated legal issues, manufacturing rights, and royalties, only 15,000 units were purchased. The M42 submachine gun was classified as a substitute standard when the M3 submachine gun was introduced. It is often stated that it used 20-round magazines, which were used in .45 ACP prototypes, but only 25-round magazines were used in the 9mm production version.