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Title:	GUN, SUBMACHINE -  U.S. SUBMACHINE GUN M3A1 .45ACP SN# 710711
Maker/Manufacturer:	HYDE & SAMPSON
Date of Manufacture:	1945
Eminent Figure:
Catalog Number:	SPAR 1552
Measurements:	OL: 29.3" with stock extended; 22 3/4" with stock retracted. BL: 8" 10.25 lbs. loaded, 8.1 lbs. unloaded

Object Description:

U.S. SUBMACHINE GUN M3A1 .45ACP SN# 710711
Manufactured by Guide Lamp Division of GM, Dayton, Ohio - Standard M3A1 "Grease Gun." Blowback-operation; full-auto fire only. 4-groove rifling; right hand twist. Stamped metal construction. Blade front; fixed aperture rear sight set for 100 yards. Cyclic rate of fire 400 rpm. Weapon weighs approximately 10.25 lbs. loaded and 8.1 lbs unloaded. Complete with 30-round detachable box magazine and olive drab canvas sling. Adopted as standard in December, 1944.

Markings:
Magazine housing: SUB MACH GUN/CAL..45 M3A1/GUIDE/Ordnance bomb/U.S. NO./710711.
Bolt cover: GL B 7161922.
Triggerguard: B*301456-4/BGR-GL.
Sling: MRT 5-52.

Weapon transferred to the Museum on 22 December 1961. At that time weapon was appraised at $50.40.

Notes: "REMARKS: Great utilization of stampings throughout. Receiver assembly is formed of two stamped halves welded together. This assembly comprises receiver, which is tubular, a pistol grip, trigger assembly housing, and magazine well. - Barrel collar, to which the barrel is pinned, screws into an internally threaded insert welded in place in front of the receiver. - A ratchet lock of spring steel is riveted to front of magazine well and locks barrel collar. - An oiler is built into grip, and oiler stylus can double as a drift to remove extractor pin. - Trigger guard, of spring steel, fits into a slot in front of pistol grip and a slot in housing assembly, holding assembly in place. By prying trigger loose, assembly may be removed. - Barrel collar has two flat cuts to facilitate stock as wrench for removing a barrel." - U.S. Army Ordnance

"In December 1944 the M3E1 Submachine Gun was adopted as Gun, Submachine, Caliber .45, M3A1, thus reclassifying the M3 as limited standard.
In April 1945 approval was granted for the replacement of the Thompson Submachine Guns, Caliber .45, M1928A1, M1, and M1A1, with the M3 and M3A1 Submachine Guns. The Thompson type submachine guns withdrawn from service were to used for International purposes.
The M3A1 Submachine Gun, like its predecessor the M3, is all metal, fabricated mainly of stamped parts to take advantage of speed and economy of manufacture and assembly. Its weight distribution, with its low cyclic rate allows unusual accuracy for a weapon of this type, whether used as pistol, or with the stock extended. The working parts are fully enclosed to protect them against dirt, water, and mud. There are no projecting moving parts to endanger the operator. The receiver assembly is fabricated from two stamped symmetrical halves, welded together. The rear sight, barrel bushing, sear pin bushings, hinge assembly and sling loops are all welded in place; and the cover, stock catch, and ratchet are added to complete the assembly. The pistol grip has incorporated therein a large capacity oil can which is made as an assembly to the pistol grip. A cap on the bottom of the pistol grip has attached thereto a stylus which serves a dual purpose, namely; as a means of oiling the gun, as well as a drift to remove the extractor retaining pin.
The bolt feature an integral firing pin, a semi-fired spring type extractor, and a finger hole for cocking, is designed to form a complete assembly with its guide rods and driving springs. Dual guide rods and springs are employed to furnish complete support and control independent to the receiver during the bolt travel. This gives accurate guiding, smoother operation, and uniformity of driving spring loaded with a minimum of wear, dirt, and lubrication troubles. The assembly is easily removed for inspection, cleaning, or convention.
A conventional integrated assembly is made of the sear, connector, trigger, and spring for ease in assembling and disassembling in the receiver.
The housing mounts the ejector, closes the opening in the bottom of the receiver, and retains all pins, the magazine catch, spring, and shield.
The stock is equipped with transverse bar to act as a stop when used as a cleaning rod to prevent injury to the barrel. This bar has a short stud incorporated wThe cover assembly insures a closed, safe gun when not in use, and protects the interior against mud, rain and dust. The integral safety lug on the cover locks the bolt forward when closed on an empty chamber, with loaded magazine in place, or retains the bolt assembly with barrel removed for shipping. In the cocked position the safety lock cams the bolt back off the sear, making the sear and trigger inoperative.
An outstanding feature is the method in which the gun may be field stripped for cleaning. No tools of any sort are required." - HISTORY OF THE DEVELOPMENT OF SMALL ARMS CONDUCTED BY THE RIFLE BRANCH DURING WORLD WAR II by E.G. Cooper.

"In December, 1944, the M3E1 submachine gun was adopted as 'Gun, Submachine, caliber .45, M3A1,' thus reclassifying the M3 as Limited Standard.
In April, 1945, approval was granted for the replacement of the THOMPSON guns, caliber .45, M1928A1, M1, and M1A1, with the M3 and M3A1 submachine guns. The THOMPSON type submachine guns withdrawn from service were to be used for international purposes." - Thomas B. Nelson

"In characteristic and general appearance, the M3A1 is basically the same as the M3. The M3A1 changes were made to further simplify design and manufacture of the M3, and to make various other small improvements indicated by combat experience. The principal changes to be found in the M3A1 are: The bolt retracting lever and handle assembly is completely eliminated; the housing assembly contains only the ejector. A cocking slot is cut into the top front of the bolt, and the ejector port and its cover are longer, to allow cocking of the bolt by inserting a finger in the cocking slot and drawing the bolt to the rear. An ejector groove is cut into the bottom of the bolt, and extends the full length of the bolt; this allows removal of the full length of the bolt; this allows removal of the bolt without taking off the housing and ejector assembly. A bracket is added to the wire stock, to act as a magazine loader. An oiler is built into the pistol grip. Flat surfaces are cut into the front of the barrel collar, to permit use of the stock as a barrel assembly wrench. The magazine catch is shielded to prevent accidental release of the magazine. The M3A1 was not issued until late in World War II, and was used in limited numbers. It received more extensive use during the Korean War." - Johnson & Lockhoven.

"The M3, and later M3A1 'grease gun,' was an Army replacement for the expensive Thompson. Unfortunately, the M3 did not develop the Thompson reputation for reliability. Magazines would eject prematurely, the bolt on the M3 A1 was difficult to retract with cold-numbed fingers and jams were less than unknown.
Until comparatively recently, this was an extremely common weapon in Third World countries as U.S. military surplus. I saw National Police in Korea carrying them on roadblock duty. In Vietnam, indigenous forces and special units often used them, as did the Viet Cong, altering their caliber as necessary." - David E. Steele

Approximately 622,163 M3 and M3A1 submachine guns were manufactured during the Second World War. At the beginning of the Korean War, another contract for M3A1s was placed with the Ithaca Gun Company for an additional 70,200 M3A1, with 33,200 manufactured. The M3A1 would also see action in the early part of the Vietnam conflict.

OCM 25593 - 11/02/1944 - Gun, Submachine, Cal..45, M3A1 (M3E1) - Recommended for Standardization.
OCM 26148 - 11/21/1944 - Gun, Submachine, Cal..45, M3A1 - Approval for Recommendation for Standardization.
OCM 26747 - 02/22/1945 - Gun, Submachine, Cal..45, M3 and M3A1 - Recommended to Replace Guns, Submachine, Cal..45, Thompson, M1928A1, Thompson, M1, and Thompson M1A1.
OCM 27393 - 04/19/1945 - Approved above recommendation.

The M3A1 Submachine Gun with flash hider is one of the few World War II era weapons still standard with US forces. It is issued as a pe
References:
Ezell, Edward. SMALL ARMS OF THE WORLD. Barnes & Noble Books. N.Y., N.Y. 1993.
Hogg, Ian V. & John S. Weeks. MILITARY SMALL ARMS OF THE 20TH CENTURY. 7th Ed. Krause Publications. Iola, Wi. 2000.
Iannamico, Frank. UNITED STATES MACHINE GUNS: FROM THE AMERICAN 180 TO THE ZX-7. Moose Lake Publishing LLC. Henderson, NV. 2004.
Johnson, George B. & Hans Bert Lockhoven. INTERNATIONAL ARMAMENT. Vol. II. International Small Arms Publishers. Cologne, Germany. 1965.
Lewis, Jack. Ed. THE GUN DIGEST BOOK OF ASSAULT RIFLES. DBI Books, Inc. Northbrook, Il. 1993.
Mullin, Timothy J. THE FIGHTING SUBMACHINE GUN, MACHINE PISTOL, AND SHOTGUN. Paladin Press. Boulder, Co. 1999.
Nelson, Thomas B. THE WORLD'S SUBMACHINE GUNS. T.B.N. Enterprises. Alexandria, Va. 1977.
U.S. Army Ordnance. SUBMACHINE GUNS. Vol. III. Aberdeen Proving Ground. Aberdeen, Md. 1959.

TM9-1217; TM 9-2171-1