My favorite crew weapon, no longer issued to tankers.
For my Favorite Ewald Sir,,,
M3 submachine gun
The M3 was an American .45-caliber submachine gun adopted for U.S. Army service on 12 December 1942, as the United States Submachine Gun, Cal. .45, M3.[5] Compared to the Thompson submachine gun, the M3 was cheaper to produce, lighter, more accurate, and was also chambered in .45 ACP.[5] The M3 was commonly referred to as the "Grease Gun" or simply "the Greaser", owing to its visual similarity to the mechanic's tool.[6]
Intended as a replacement for the .45-caliber Thompson series of submachine guns, the M3 and its improved successor, the M3A1 began to replace the Thompson in first-line service in late 1944 and early 1945. Due to delays caused by production issues and approved specification changes, the M3/M3A1 saw relatively little combat use in World War II.
Design details
The M3 was an automatic, air-cooled blowback-operated weapon that fired from an open bolt. Constructed of plain .060-in. thick sheet steel, the M3 receiver was stamped in two halves that were then welded together.[5] The M3 was striker-fired, with a fixed firing pin contained inside the bolt. The bolt was drilled longitudinally to support two parallel guide rods, upon which were mounted twin return (recoil) springs. This configuration allowed for larger machining tolerances while providing operating clearance in the event of dust, sand, or mud ingress.[17] The M3 featured a spring-loaded extractor which was housed inside the bolt head, while the ejector was located in the trigger group.[18] Like the British Sten, time and expense was saved by cold-swaging the M3's barrel.[5]
[edit]Operating mechanism
A diagram of the M3 illustrating function.
The M3 operating sequence is as follows: the bolt is cocked to the rear using the cocking handle located on the right side of the ejector housing. When the trigger is pulled, the bolt is driven forward by the recoil springs, stripping a round from the feed lips of the magazine and guiding the round into the chamber. The bolt then continues forward and the firing pin strikes the cartridge primer, igniting the round, resulting in a high-pressure impulse, forcing the bolt back against the resistance of the recoil springs and the inertial mass of the bolt. By the time the bolt and empty casing have moved far enough to the rear to open the chamber, the bullet has left the barrel and pressure in the barrel has dropped to a safe level. The M3's comparatively low cyclic rate was a function of the relatively low pressure generated by the .45 ACP round, a heavy bolt, and recoil springs with a lighter-than-normal compression rate.[citation needed]
[edit]Features
M3 receiver markings
The gun used metal stamping and pressing, spot welding and welding extensively in its construction, reducing the number of man-hours required to assemble a unit. Only the barrel, bolt and firing mechanism were precision machined. The receiver consisted of two sheet metal halves welded together to form a cylinder. At the front end was a knurled metal cap which was used to retain the removable barrel. The cold-swaged, rifled barrel had 4 right-hand grooves. M3 and M3A1 submachine guns could be fitted with an optional, detachable flash hider, though none saw any service in World War II.[19] A later production flash hider designated Hider, Flash M9 was produced in time to see service during the Korean War. It proved popular in combat, as frequent night engagements emphasized the need to reduce flash signatures on small arms. In Korea, U.S. soldiers equipped with automatic weapons were taught to look above the flash of their weapon during night firing, a tactic that sometimes prevented the detection of crawling enemy infiltrators and sappers.[citation needed]
Projecting to the rear was a one-piece wire stock made from a formed steel rod that telescoped into tubes on both sides of the receiver. Both ends of the stock were tapped and drilled so that it could be used as a cleaning rod. It could also be used as a disassembly tool or as a wrench used to unscrew the barrel cap.[citation needed]
The M3's Cocking handle assembly was located on the right-hand side of the receiver on the ejector housing, just forward and above the trigger, and consisted of nine parts.[17] As the handle is pulled to the rear, a pawl rises to engage a notch in the bottom of the bolt, pushing the bolt to the rear until it locked back on the sear.
The fixed sights consisted of a rear aperture sight preset for firing at 100 yards (approximately 91 m) and a front blade foresight. All M3 submachine guns were test-fired for accuracy at a distance of 100 feet (30 m).[5] With the sights set at six-o'clock on a bullseye target, each gun was required to keep four out of five shots within or cut the edge of a three-inch (76 mm) bulls' eye to meet accuracy requirements.[5]
The weapon's only safety was the hinged ejection port dust cover. This cover had a projection on the underside that engaged a notch on the bolt, locking it in either its forward or rearmost positions. The M3 had no mechanical means of disabling the trigger, and the insertion of a loaded magazine would load the gun. With receiver walls made of relatively thin-gauge sheet metal, the M3/M3A1 were subject to disabling damage if dropped on an open dust cover - the covers bent easily, negating the safety feature. Dropping the gun on a sharp or hard surface could dent the receiver enough to bind the bolt.[citation needed]
The M3/M3A1's 30-round magazine was the source of complaint throughout the service life of the weapon.[20][21] Unlike the Thompson, the M3 fed from a double-column, single-feed detachable box magazine which held 30 rounds and was patterned after the British Sten magazine; the single-feed design proved difficult to load by hand, and was more easily jammed by mud, dust, and dirt than double-column, double-feed designs like the Thompson.[22] Additionally, the feed lips of the single-feed design proved more susceptible to feed malfunctions when slightly bent or damaged. Plastic dust caps were later issued to cover the feed end of the magazine and keep out dust as well as protect the sensitive feed lips
Shooting the M3 Grease Gun - YouTube
M3 ''Grease Gun'' Shooting by SkilledAmateur - YouTube