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. I’m not sure why the author said southpaws were out of luck. I used to own a M3A1 and only shot if left-handed. It is so slow firing that you could sing a song while using it:

    The stars at night,
    Are big and bright,
    Pop – Pop – Pop,
    Deep in the heart of Texas.

    The prairie sky,
    Is wide and high,
    Pop – Pop – Pop,
    Deep in the heart of Texas.

  2. I’ve never held or even seen one, but I have fired the MP-40 and liked it a lot. I imagine they are similar enough that the Grease Gun would be as good to shoot and handle.

    I appreciate good designs and engineering, but I love something that just works and gets the job done for a reasonable amount of money. If they had kits for these like the Sten, I’d build one of each. Maybe one day Cody Wilson will offer 3D printer files on these weapons.

    1. They are available from time to time on auction sites, just expect to spend a pretty penny, I saw a decent kit recently for $2500 as a starting bid!

  3. I won a pair of 10 ya pistol griped, 12 inch barrels in a card game with four box’s of brass, 00 buck, shells.
    Shot it once! Was more weapon than I wanted to have and I didn’t think that wearing wrist braces for the remainder of my life was going to be a good fashion statement.
    I traded them to a Marine tunnel rat in 72 for an M3A1, an ten mags. Was my daily carry from then on. Very stable platform, cyclic was a bit low but allowed for good control and shot placement. However, the .45 ACP chambering made up for any short comings. Had or armored clean the trigger up a bit but other than has been kept original. Was my constant companion back in the day. Served me very well. I consider it to be one of the better sub guns produced from that period. Will be found yet on battle fields here an there even with the proliferation of AR an AK platforms.
    I also had a Swedish K, 9mm sub-Gun for a time 11that I also liked very much. Would have liked to have kept it too.

    1. Great story, thanks for your service! If you’ve still got it, I would gladly take good care of it for you!

    2. Hey George! I’ll be happy to put you on the list of those who would like to care take what I have collected over the years! You can all come to an agreement when gone, LOL!
      I would have liked to have kept that brace of 10ga double pistols too. I do know that they came home with the Marine I traded them too and he and they live in Wyoming now. We have stayed in touch an I see he an his wife now an again. He grew quite fond of them for clearing tunnels. As we are both getting older I don’t suppose he shoots them very often but they look quite good hanging on his wall with othe memories of his youth. Im sure his grand kids will get them along with the story of them someday.
      If you ever get the oppertunity to have sone range time with one try the Seidish K in 9mm (or a S&W M76). This platform was also quite comfortable and served very well.

  4. We had the M3A1 on our tanks in Vietnam. One day while cleaning all of the tank weapons, one of my crew said “LT, the springs on the 50 cal machine gun are the same as the grease gun except longer”. Sure enough, he was correct. So we cut the 50 cal springs to size, installed them in the grease gun and loaded it. Everyone stood back while I pulled the trigger. The springs were so strong that when I pulled the trigger all 30 rounds fired in about 1 second. It was unbelievable.

    1. That’s a ROF of about 1800 rpm.Faster than an MG42.
      While it is possible to increase the ROF of a gun with stronger springs, simply adding a stronger spring has side effects, and the increase in ROF is modest.
      Increasing the ROF by over 3x by simply installing a stronger spring just isn’t possible.
      The spring doesn’t only push the bolt forward; it also slows the bolt as it moves rearward. If the spring is too strong, it won’t allow a spent casing to eject because it will stop the bolt before it goes all the way back, much less pick up a new round to feed.
      I have no doubt it probably felt that fast, but physics is a harsh mistress, and won’t allow what you remember.

  5. My dad was a tanker with Patton in WW2 he used a greaser himself said he could cut a man in half from the turret of that that tank with a short burst from the greaser .He loved it as a tanker weapon .

    1. We had them up at the firebase camp in the highlands where my unit did OJT for ARVN Special Forces in ’68 and we also gave them the surplus M2 select fire .30 carbines to better ‘fit’ their diminutive size. The rate of fire was just too slow for extreme fast action jungle fighting. Of course, that’s why each team had at least one Pig along for the party, and the rest of us wore belts of a hundred rounds or so in crossed links. But cyclic was so slow in the Grease guns that a fast trigger finger on the M2 in semi mode could beat the greaser firing full auto! For extended carry with sufficient fire fight ammo, it was, like the 14, just to heavy to carry around all day. The Swedish K, which was later ‘knocked off’ by Smith & Wesson, as a police subgun, I believe, was a gem, with the 36 round mags, but the one I really liked (we had just about everything that ever was used in warfare whistle through our base camp at one time or another) was the Suomi with the top folding stock as it could also accept 72 drum magazines in 9mm. We modified the front of the barrel with a modified type of silencer/flash suppressor and this was like brass knucks in a bar room brawl for surprise night time ambushes. Then the CAR 15 ‘Shorty carbine came around with 30 round Mags that was light enough to be handled effectively with one hand, like a pistol, with lightning fast drop free mag changes compared to anything else and that became the preferred date for the dance death for most of us.

  6. It was someone named Steve that said that, he also said he was a door gunner on the Space Shuttle in Nam along with a few other “Out There” Comments.

    As for the grease gun being used in Desert Storm I can attest that it was in fact used. There were still quite a few units with them still in their inventory. 3rd Infantry Division for one. Almost anyone assigned to a tracked vehicle was issued one, even in the 103rd M.I. BN not just the Armored and Tank units. I personally loved them. If I could get my hands on one today I would pay the BS fees to have it. It was fun to shoot, easy to maintain, would take a beating and not miss a beat or complain about it.

    1. I myself never saw anyone with the M3 greaser in DESERT STORM that was my experience end of it .

    2. I was an armor crewman (19k10) from 1989 to 1993. I familiarized on the M3 and qualified on the M16A2 as the crew served weapon and the Beretta M9 as the personal weapon in OSUT. When I arrived in Europe with 1AD we were using the M16A2 and 1911’s. I was with 1AD, TF1-37 during Operation Desert Storm and our unit carried these. There were no M3 Grease Guns in our armory. When I returned stateside in 1992 the unit I was assigned to did not have them either. I could understand maybe some units still clinging onto them but I know that wasn’t the case in the units with which I served.

    3. There are some transferable greasers out there, just expect to spend quite a bit, it’s worth it mind you, but very pricey!

  7. My early military training was with M1 Garand, carbine and 1911 then was issued an M3A1 on arrival at one assignment, and carried for that assignment duration. Typical to AOR rear areas never qualified, fired or even had a magazine for the arm, but it was very handy daily carry as opposed to the usual M1 Carbine. Only issued a Garand while on rifle team then came the M14 era soon followed by the M16. Served 1952 thru 1980.

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