Before the arrival of the various classic American firearms of World War 2 such as the M1 Thompson, M1 Garand and M1 Carbine, the United States pressed into service many lesser-known firearms that proved both available or promising. This opened up the field to various talented gunsmiths to extend their wares and expertise in attempting to fill the vast inventory requirements of the United States military. Of course, the lesser-name firearms failed the US standard in some way - being too delicate in the field, too expensive to produce in the numbers required or too faulty in their general design to be of much military service. For the Reising Model 50 (M50) series of submachine guns, the undoing proved to be its complex internal arrangement and function which led to many stoppages in the heat-of-battle. As such, the weapon received a relatively short service life in American frontline hands.
Design of the Reising (attributed to Eugene Reising, having worked at once point with legendary gunsmith John Browning) began prior to American involvement in World War 2 in 1940. Reising secured a patent for his new weapon the same year and partnered with Harrington & Richardson Arms Company to produce it, the weapon to bear the name of "Reising" for its life. The firearm utilized a close-bolt mechanism which required multiple internal functions to work properly in succession following each press of the trigger. The internal working components were housed in a metal frame which was further set within a wooden service-rifle-style body integrating the pistol grip and shoulder stock. The frame was partially exposed along the top of the wooden body which gave access to the sights and ejection port. The barrel sported cooling fins to help prevent overheating and was supported throughout its length underneath by the wooden body which continued forward as the forend for the supporting hand. A long Cutts compensator capped the muzzle end of the barrel. The magazine was fed through a bottom well directly under the ejection port and well ahead of the trigger unit. The trigger was conventional, seated under the rear portion of the receiver and ahead of the pistol grip within an oblong trigger ring. A cocking lever was seated in a slot under the forend, hidden from view. The weapon was chambered for the .45 ACP cartridge, the same as in the Colt M1911 semi-automatic pistol and the M1 Thompson, and fed through a 12- or 20-round detachable box magazine. The gun measured an overall length of 35.75 inches with an 11 inch barrel and sported a weight of 6lbs, 12 ounces. It was a select-fire weapon capable of semi- and full-automatic modes. An optional adjustable shoulder sling could be fitted for ease of transport.
Production of the Reising began in late 1941 and the type was adopted for service as the "M50" with the United States Marine Corps (the US Army had rejected the Reising after trials due to its maintenance requirements). Manufacture spanned through to the end of the war in 1945 under the Harrington & Richardson Arms Company (Worchester, Massachusetts) brand label. Performance included a rate-of-fire of 550 rounds per minute and the .45 ACP cartridge was a proven man-stopper while the general appearance of the weapon was sleek.
While the M50 was a serviceable weapon in a controlled environment, its complicated internal arrangement was wholly inadequate for military frontline use. It was quickly found - through American US Marine actions at Guadalcanal and Bougainville - that dirt and debris, unavoidable in the field, could jam the action and general fouling caused by the breech-locking process could furthermore render the weapon useless at the worst possible times. Problems with the weapon proved so persistent that many service members gladly dropped their Reisings in favor of whatever other weapon became available during the course of the fighting. As other, more refined, firearms became available in useful numbers (primarily the M1 Carbine), the Reising was retired from frontline use and relegated stateside for security and policing for the duration of the war. In this role, lacking the abuse inherent in a battlefield setting, Reisings performed as expected.
For the short time that the American military made use of "Paramarines" - marine paratroopers - Reising attempted to sell a lightened, shortened and modified form of their Model 50 as the "Model 55". The Model 55 brought about use of a folding wire stock and shortened barrel assembly lacking the Cutts compensator. The wire stock folded over the left side of the body while the pistol grip was well-formed for ergonomics and formed vertically in its appearance. The result was a 31-inch long weapon with a lowered rate-of-fire of 500 rounds per minute. All other facets of the Reising design remained including the complex internal working. As such, the weapon was not really an improvement over the original and inherited all of its existing limitations. Like the Model 50 before it, the Model 55 was no more a commercial nor military success. As an aside, the US military establishment eventually dropped its dedicated marine paratrooper force before the end of the war in February of 1944.
A pair of semi-automatic fire only forms emerged from the Model 50 line and this included the M60 and M65. The Model 60 was intended as a carbine rifle-type implement and chambered for the .30 Carbine cartridge. The Model 65 was a training version of said carbine, chambered for the .22 Long Rifle rimfire cartridge.
The Reising M50 and M55 served until 1953 and some 100,000 examples were produced until 1945. Stocks of Reising submachine guns were also sold to the United Kingdom and issued to the Canadian Army. The Soviet Union received the type under the Lend-Lease agreement. Other operators went on to include Iceland and the Philippines.