Throwback Thursday: The M3A1 Grease Gun — A Desperate Gun for Desperate Times

A surplus submachine Grease Gun

A soldier’s connection to his equipment is an odd bond. As a warrior your very life might hang on the effectiveness of your gear, and you need to believe that the equipment you use is the very best your nation can produce. In no other aspect of military service is this axiom better exemplified than in the case of a soldier’s personal weapon.

By Will Dabbs

The Second World War was the most expansive conflict in human history. Never before or since have so many combatant nations tried to resolve their differences on the battlefield. At a time when Total War demanded every measure of effort industrial, economic, and spiritual that a nation might muster, the United States attempted to produce a quality submachine gun that was both effective and inexpensive while remaining amenable to mass production.

The Grease Gun

A surplus submachine Grease Gun
The M3A1 was comprised of two stamped, sheet metal halves welded together. The heavy bolt rode on twin guide rods so the internal geometry of the receiver was not terribly critical.

The original M3 Grease Gun was adopted in December of 1942. In its original form, the gun was intended to be disposable so spare parts were not stockpiled. The M1A1 Thompson it replaced costs $42 at the time as opposed to $18 for the M3 and $9 for the even more utilitarian British Sten. To grant a bit of perspective, in today’s dollars this is $554, $237, and $118 respectively. By December of 1944, a number of deficiencies had been identified and corrected, and the definitive M3A1 was rolling off the lines. This variant of the gun served as personal armament for tank crews well into the 1990s.

The M3A1 was comprised of two stamped sheet metal halves welded together. The heavy bolt rode on twin guide rods so the internal geometry of the receiver was not terribly critical. The original M3 cocked by means of a ratcheting sheet steel handle that was wont to bend and break under hard use. By contrast, the M3A1 cocked by means of a simple divot in the bolt. Any handy human finger could cock the bolt easily. The pivoting dust cover incorporated a blocking device that locked the bolt either forward or back and served as a rudimentary safety. The wire stock could be removed and used as a handy magazine loader to pack 30 .45 ACP rounds into its double-column magazines that tapered to a single column for final feeding.

WWII reenactor with OD green BDUs and a Grease Gun
Many period photographs show Greasers in action with a pair of magazines taped back to back. The supply system offered rubber covers that slipped over the top of loaded magazines to keep water and crud out.

Turning Ammunition Into Noise

The Grease Gun’s rate of fire is remarkably sedate. At 450 to 500 rounds per minute, singles are easy with a delicate touch on the trigger. A full magazine dump takes a nice long time. Despite the heavy cartridge, the classic Grease Gun remains remarkably controllable.

Some GIs believed the rate of fire was too slow for proper room clearing, but a friend who carried one in action swore by the gun. Many period photographs show Greasers in action with a pair of magazines taped back to back. The supply system offered rubber covers that slipped over the top of loaded magazines to keep water and crud out.

Most GIs invariably preferred the Thompson, despite its excessive weight and bulk, but the vintage Greaser was compact and easy to carry while still throwing those heavy nearly half-inch slugs in a reliable swarm. The wire stock is neither comfortable or terribly effective, and left-handed operators were simply out of luck. However, at a time when nation states were giving their all to either fall or prevail, the Grease Gun was available in quantity on the battlefield. Handy enough to tuck into the fighting compartment of a Sherman tank or across a reserve chute for a combat jump, the M3A1 Grease Gun was a desperate tool for desperate times.


Dr. Will Dabbs was raised in Clarksdale in the heart of the Mississippi delta. He attended Ole Miss and earned a degree in Mechanical Engineering while being commissioned as a Second Lieutenant in the Regular Army. After eight years on active duty Dr. Dabbs left the Army as a Major with 1,100 flight hours piloting UH-1H, OH-58A/C, CH-47D, and AH-1S helicopters. He then attended medical school and a Family Medicine residency at the University Medical Center in Jackson. He was married in 1987 to his high school sweetheart and they have three children. Dr. Dabbs’ hobbies include tactical shooting, reading, commercial writing, woodworking, firearms design and manufacturing, and teaching the Young Married Sunday School class at First Baptist Church Oxford.

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Comments (56)

  1. My ol man swore by his said same thing it would drop a German ss or italian with 1 round ,was very easy to use coming out of a tank and if the tank was disabled along with the M1911 and M3 they could fight there way back to the line and live to fight another day and it would make a pewrfect urban close range or jungle adapted new model would be something to see compared to the price of building the M4 AR how bout updating the ol M3 greaser .45 type weapons platforms both were very good manstoppers.. Why we ever went to the 9mm over a .45 i never understood anyhow ol slab sides still gets the job done 100 yrs later plus.

  2. The movie “Hell is for Heroes” demonstrates the proper handling of the M3 to perfection.

    Having shot both the Thompson and the M#, I’d choose the Grease Gun any day…

  3. Replacing the recoil springs on the M3 grease gun with an M2 50 cal recoil spring halved doubled the rate of fire of the grease gun. Worked great but consumed ammo quickly. A Vietnam modification.

    1. Yep, did this in Nam. The trick was ehere to cut the M2 spring. That made all the difference in the world. I was in CIA at the embassy during Tet. The Marines in the Security Guard contingent used Beretta M12’s with 9MM and we CIA MACV-SOG analysts and interpreters carried M3A1’s. We’d use the Beretta’s to do the initial sweep and the M3A1’s to hit the harder behind the wall targets as we cleaned up the embassy of VC sappers. Good, effective cheap urban gun for up front and personal combat survival.

  4. A friend carried one in Vietnam, while I carried a M-2 Carbine. We both got our weapons from a most unlikely source, a V.C. tax collector. Those of you that were over there know of them. For his own reasons, he supplied both to me and friend, ‘string free’. He expected nothing, we gave nothing, except an occasional beer, when we encountered him.
    My friend, an MP, was very happy with his ‘Grease Gun’. It relatively slow rate of fire made it easy to control. It’s slow, heavy bullets would knock down a target easily. I really envied him. My M-2 with it’s higher rate of fire was sometimes difficult to control under ‘full-auto’ conditions. Though, the .30 cal. bullet was no slouch as a man stopper, it was just difficult to control, firing from a window and driving a vehicle at the same time.

  5. I qualified on the M3 in AIT, and was issued one in Germany (1960). When arriving in “Nam (the M-16 was new and considered a Suicide weapon) I obtained an M3 and my First Sgt carried a Thompson. We carried these until threatened with a court martial if we did not get rid of them. I considered the M3 perfect for urban and jungle warfare, simple,short , and firing a man stopper round. Need to go back to them.

  6. I acquired and carried an M3A1 for a time in SEA. I liked it very much for both the .45acp and lower cyclic rate. I traded it for a Swedish K which I cared for the remainder of my tours. The K was a bit lighter as I remember and one could carry more munitions to weight for it. Had a big higher cyclic rate and 9mm was easer for me to acquire in quantity than .45 ACP.
    Both platforms served me well.

  7. I was trained on and issued a Thompson while in the Navy. I had handled the M3A1, but felt the Thompson was a better weapon. If I had to carry it in the field I might not have thought the same as a matter of practicality. The Thompson was truly a work of art IMHO. Sure wish I could afford one today.

  8. I was an Armor Officer long enough ago that as a 2nd Lt, we actually had the M3s for one trip to the range. While I had to qualify with my 1911, all we were required to do with the M3s was to shoot for familiarization.

    I recall that we would just point to the lower left hand corner of the silhouette and fire a 7-10 round burst. When we would let off the trigger and look, there was a nice line of .45 cal holes going from the lower left to the upper right of the target. Helluva lot of fun and it would have dropped anyone!

    That was the only time we shot them because they switched us out for CAR 15s soon after. Much nicer weapon, but not as much fun to shoot.

  9. As beautiful as the “Thompson” was both in looks and as a machine, the “grease gun” made more sense in a war as large as WWII, Lighter,cheaper and as reliable. The “Thompson” made for a better police arm, Being somewhat over built it’s more suitable as a weapon intended to be kept around for many years.

  10. My father was a tanker under patton in ww2,north africa ,anzio as well and belgium, of course he swore by his old grease gun in the role he used it for being in a sherman his opinion was that for a tank crew this was the Answer and they all had M1911 colts as well before he got issued the greaser he was using an m1 carbine that is what they had at the time in the tanks .He was always saying how that .45 cal M3 got the job done way better than the M1 carbine and held more rounds and could carry more ammo for it in the tank and was used in his sidearm as well .One great example of good old American ingenuity at work and great use of our industrial might to keep that war effort alive .Both fired same round giving the tank crews far more firepower in the manner it was needed most .Saved countless American lives and served for many many yrs.

    1. @Damian

      My father was also a tanker in North Africa, but didn’t go ashore in Italy until Salerno. He wasn’t at Anzio but did make the Rapido River crossing. He spent time on Tank Destroyers. I still have his regimental booklet they gave out as well as an original Road to Rome booklet the 5th Army published.

      They also had M1 carbines, but were glad to get the grease guns, although he also kept a Garand on the tank and said he was glad to have it once when their tank hit a mine and they had to bail during an assault.disabled tank

    2. Dad was with the 20th Armored Division. Landed at Omaha on day one, was there for the Bulge and was in the Africa landings and campaign prior to that. Spoke highly of the Thompson and his Tanker Grand too.

    3. @ mikhail My dad said there were many many times those tank destroyers saved their asses from those big tiger tanks they had in belgium without them we may have lost that battle and war could have went on a lot longer they would always be thankful when 4 or 5 destoyers showed up and took those huge tiger tanks out from distance they were a very frightful sight in a tiny sherman when you saw a squad of tigers on move you had 1 shot in a sherman up against a tiger you miss the sweet spot better bail fast he will not miss they are Germans he would say . They never miss . Hi 5’S to ya father my man could have saved my dads life at one time who knows we were not there . Were many times without them tank destroyers they would NOT have survived against those tiger tanks dad said they wrre massive and very hard to kill and could shoot them wayyyy before they could get within range had to mix in with them in huge numbers or all died.Only way to beat a tiger tank at the time .

    4. @Damian

      My dad spent time in both. Started in Shermans and then was transferred to the destroyers. Nasty gun, but an open turret.

      Cameras were a lot less convenient in those days than now, so not too many pictures, but I do have a few old B&Ws he had of some Shermans, a destroyed MkIV, some very badly trashed Italian villages, and a captured German officer. I also have his unit picture from his old horse artillery unit from back in the mid-30s. Great stuff!

    5. Cool the sherman gun was like pea shooter against those big tigers the destroyers had enough gun and could hit them at long range shermans could not do the 77 mm was nothing against those big tiger and other 88’s most just bounced off had to mix in with them and hit it dead in rear or tread at short range to stop them only way but the detroyers big guns blew them up with 1 round without those crews and that gun it could have went on much longer and many many more tank crews would have died. they got the job done .

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