Book Review: The US M3/M3A1 Submachine Gun by Michael Heidler

It is a bit surprising that there has not previously been a significant book written on the M3 “Grease Gun” submachine gun – but Michael Heidler has corrected that empty space in the firearms literature. His new book “The US M3/M3A1 Submachine Gun” is 224 pages covering all aspects of the Grease Gun’s development, manufacture service, and accessories.

The M3 was the American second-generation SMG, developed for maximum simplicity and production economy. Heidler covers more than a dozen different proposed guns that competed for adoption before the M3, and also discusses the development of the T-15 and T-20 guns that became the M3. This includes specific testing procedures and trials reports. He then explains the mechanics and disassembly of the gun, and goes into detail about its manufacture. The M3 was produced by GM’s Guide Lamp division, a company specializing in sheet metal stampings that was an excellent choice for the new design.

As the M3 saw field use a number of shortcomings came to light, resulting in the improved M3A1 variation. Production only ran for a couple years however, ending in the summer of 1945 once enough guns were in inventory to fulfill American military needs. A relatively sparse number of accessories were made, which are also covered in the book. In addition, Heidler has some discussion of experimental patterns (like the curved-barrel types, 9x19mm conversions, silenced models, and .30 Carbine experiments) and foreign production copies of the M3.

Overall, the book is an excellent source for all things Grease Gun. The text is a bit short in some places, buoyed by a lot of photographs, both period original pictures and images or guns and parts. I would have liked to see it go a bit more in-depth in some areas, but there simply might not be much more detail available. This was not a gun that had an extensive service life or a complex production history, after all. It is a classic and essential piece of US military history, though, and it is nice to finally have a book covering it.

At the time of this writing the cover price is an even $45.00 and it is available from the publisher directly:
The US M3/M3A1 Submachine Gun

Or from Amazon:


  1. Between how it was designed and built, and how well it lasted, we should stay amazed. Especially since it was a last-ditch equivalent (meaning cheap) weapon not meant to last past the war. One of those few industrial items that turned out so much better than it had to be, by accident. (The Model T and Model A Fords were meant to last, the Opel 1900 was not …). Anyway many thanks for making the public more aware of this book.

  2. From several reports, the M3 & M3A1 made it all the way into the Gulf War in armor, so a pretty lengthy service life.

    • A Desert Storm Vet friend told me that his Armoured Unit still had a few M3s when they deployed to the Gulf in ’90. He emphasized the fact they had cranks !

  3. Here is a little story of mine that you might find informative. I was in the Mississippi National Guard (last to get anything new and the first to get called out on that fact), and we used the M3/M3A1 up until the mid 90’s and trained on them. (Ian would understand that we called them “giggle” guns!) But, with training, you have to clean them too and so we did. We had several that were dang near smooth-bores, and someone once took a .45 round and placed it in the muzzle and it DROPPED clean thru the barrel! Not just the bullet but the whole round! Now that is what we called “SHOT OUT!”

    • “several that were dang near smooth-bores” – A bore diameter that began at .442″ almost wore down to .452″ (groove diameter)? That I can certainly believe.

      Another .442″ bore wore to over .480″ (rim diameter)?

      And it did so via shooting (which takes place when the .473″ case mouth comes to rest on the ~.452″ shoulder of the chamber, stopping any further forward motion of the cartridge as the firing pin continues forward)? Oooo – K . . .

      • I suppose the question here is that did Jeffrey Harville actually SEE that happening or did he only hear a story? And if he did see it happening, is he sure that it was a bona fide .45 ACP round and not something different (like a 9mm round for example)?

        • I would add that most “shot out” barrels were/are more properly described as “cleaned out” barrels. Metal bore brushes vigorously applied by troops in a hurry to get the weapon turned in will cause much more wear than simply firing the piece. And, of course, there is always one emergent leader who discovers that if you trickle a little sand on the brush it goes ever so much faster. You are effectively sandpapering the inside of the barrel but boy it sure gets it good and shiney don’t it? There are various jokes about GIs and what they can do to a cast iron cannonball. Those of us who have been GI wranglers tell those jokes only half in jest.
          Wafa Wafa Wasara Wasara

        • “…actually SEE that happening or did he only hear a story?..”(C)

          This is called “Mandela syndrome”.
          Probably from the same area as “AK47 breaks through the railroad rail”.

      • Not shooting – the Guard doesn’t get enough ammo to wear out bores via shooting. But via cleaning over 50 years? W/ no spare bbls still in the system, nor a supply SGT who knows how to order such a thing? And not enough CLP to go around? I can see an M3 bbl brushed out like someone took a Dremel to it – and in 50 years, I’ll bet someone did…

  4. Did the book cover the bent barrel that was designed for shooting around corners? I have seen several photos of them. I can’t imagine being stuck with it.

  5. Sometime when you are in Iowa, stop by the Iowa Gold Star Military Museum and I will show you our M3E1. It is a transitional prototype between the M3 and M3A1. There were only six .45 caliber E1s made. Does the book mention the three M3E1s in .30 carbine?

  6. I was stationed in Korea in the Army circa 1995-1996, after the first Gulf War. I was in the 2nd Engineers, 2nd Infantry Division.

    We still used the M3A1 for crewmen weapons on the CEV (Combat Engineer Vehicle, an M60 tank with a spigot mortar instead of a main gun and a dozer blade and A frame hoist for engineering stuff), the ACE (Armored Combat Earthmover) and on the AVLB (Armored Vehicle Launched Bridge on an M48 tank chassis)

    You read that right, 100% guaranteed factual, that in 1996 the Active Duty US Army was still using M3A1 Grease Guns, and also armored vehicles based on M60 and M48 tanks….. in Korea, where there was an actual threat… Talk about an antique road show and a logistical nightmare!!!

  7. Thanks Ian,
    I have one of the few semi-auto versions of the M3-A1 manufactured by Valkyrie Arms in Oregon, should be a great read.

  8. Sorry for the error, Valkyrie Arms is in Olympia Washington, not Oregon.
    Unfortunately Valerie had to shut down in June 2020 due to health issues,
    She was one of the more gifted “Gunsmiths” I have had the privilege of doing business with.

  9. In 2008, one of the Seattle PD Armorers let me shoot an M-3 he found in the armory. It was a joy to shoot, with the ‘pup-pup-pup’ slow rate of fire making it easy to hit at 50 yards.

  10. I once saw at a french gun show about 15 years ago a neutrilized version of the m3 with a sten style bolt handle and a slot milled into the body for it to travel in. Unfortunatly I didnt get a look at the markings

  11. The reason for the longevity in Armor units is due to the SMG being 45 caliber, the same as the sidearm issued to tank crewmen, the M1911A1. Once a unit got 9mm M9’s, the Colts and SMG’s were turned in. The tankers now got M4 carbines – one of the original reasons for which was to replace the M3A1’s when Army converted to 9mm. And, I take the “cranked gun” (meaning M3’s) with a grain of salt. Anything is possible, but the for M3’s still being around in the active army, fifty years after being replaced by the M3A1…39000 were built new and most of the M3’s on active duty at that time were supposedly upgraded to M3A! configuration, so there were plenty for us tankers to play with, once it was no longer general issue.

    • Weird things turn up out of nowhere, in the twilight zone that is the Army’s depot system.

      I would not be a bit surprised if there were still some original M3 SMGs still lurking out there in some forgotten corner, which has yet to be brought back into the light.

      Circa 1990, I’m in Chicago picking up new GSA sedans for our recruiting station. Go to the office, meet the GSA rep, drive out into the multi-level yards to find the cars. Find three; number four is AWOL, not in the prescribed location. Go back to office, find supervisor, wind up on a marathon manual search through the physical storage areas. At one point, we drive by a cage filled with dusty construction equipment–backhoes, excavators, and other such equipment. Supervisor I’m with stops, gets out, looks everything over, and then gets back into the truck with me, swearing. We have just found a missing set of construction equipment that was originally procured for some federal project with the National Park Service, and which has been lost in the system for some 12 years or so, at that point. Must have been at least a dozen pieces of equipment there, all brand-new and covered in thick dust. The guy I was with told me that the paperwork for that equipment had been bouncing between the GSA local office and whoever it belonged to for a decade, the GSA insisting it had been picked up, and the people it was for insisting they never got it. The location in the warehouse we found it in was carried as being empty, and because the left hand never knows what the right hand was doing, nobody ever figured it out or paid attention to it, until that supervisor and I drove by it by complete accident. And, if he hadn’t known about the issue from trying to figure out where that equipment had gone…? He’d have driven by without paying the slightest attention to it.

      Army depot systems aren’t much different. Circa 1985, we got issued a bunch of demo materials all dated from the mid-1940s. TNT blocks, shaped charges, all that stuff–And, upon inquiry with the guys at QASAS as to why it wasn’t detonating reliably or thoroughly, we found out: It was stuff that had been collected up during the final period of WWII, then put into storage after a quick survey/rehab and completely forgotten about. They found it, gave it to us, and then acted all surprised we were PO’ed about having to spend days working with EOD to find all the little undetonated chunks of TNT blocks that were scattered all over the demo range…

      I have no idea how the hell you “lose” high explosives in the ammunition storage/supply system, but according to friends of mine who work in that world, it ain’t exactly unheard of. I had to pick up stuff from a NATO depot run by the Germans, one time, and it was an education–We were breaking locks off of things that I swear hadn’t been touched since the 1940s, and there were all kinds of “interesting” things stored in those bunkers and igloos. One of them still had crates inside with the Nazi eagle stenciled on the sides, and the German civilian employee I was with just looked, sucked in his cheeks, and muttered something dark about “more damn work”.

      So, yeah… Someone tells me they got issued something from long ago…? I’m not going to argue; they could be mistaken, deluded, or… It could have actually happened.

    • M4 instead of M3?
      Excellent cost savings.
      And together with the brain.
      The only way to stop the guy running out of the corner with an AT grenade in hand is with a rifle, lying on the turret roof next to your commander’s hatch.
      And at the most interesting moment, you discover that this damned shorty, after a day of driving on dirt roads, is so dusty that it does not work…
      You have saved an additional item in the BOM.
      And at the same time they received a new tank instead of the damaged or burned one together with the new crew, instead of the wounded or killed.

      • The M16/M4 susceptibility to dust as a causative factor for failure is vastly overstated. It’s amazing just how much filth can be in one of those things, and still have it function–I witnessed weapons that support soldiers had been carrying for months in Iraq without significant care or maintenance being done on them fire perfectly well on ranges our Sergeant Major threw at them off the cuff, with the intent to demonstrate the “why” that they should be doing the neglected cleaning and maintenance. He’d find someone’s weapon that was literally filth-ridden to the point where there was dust filling the trigger mechanism, take them out to the range, and the things still functioned adequately well.

        The M16 is a lot of things, but prone to failure due to dust ain’t one of them. Corrosion? Yeah; maybe. There wasn’t a lot of that, in the desert.

        I used to buy into the whole “M16 is a POS that has to be scrupulously maintained” idea, but I’m no longer so sure of that. It’s true that the amount of crap which accumulates in the mechanism firing blanks will create issues for them in very short order, but the reality of firing live ammo is a far different thing.

        So long as you keep them well-lubricated, the filth doesn’t really cause all that much in the way of trouble. Corrosion? Yes; that’s a problem. Anything else, the system chews through, and I think that the so-called “direct gas” system actually serves to blow most of the munge out of the weapon as it cycles.

        • Kirk,
          Extremely well stated, and closely mirrors the history of my own views on the subject.

          Experience with blanks in accession training (we used to describe the firing sequence as “peanut-butta-JAM” [2-4 rounds before a stoppage]) seemed to confirm the “Jam-16” reputation all the gun rags complained about. Subsequent research and experience showed otherwise.

          • Don’t confuse your shooting range with practical reality.
            How not to confuse Persian dust with Sinai or Afghan dust.
            And leave all your theoretical ones as POS at home with the rest of the rubbish.
            Real life is not guided by polygon reports.

          • People keep telling me about this super-dust that causes failure, but I’ve yet to see it in real life.

            Kuwait, Iraq, Mojave… The ultra-fine “moondust” in all three is not all that different, and I seriously doubt that the dust in Afghanistan is any finer or worse for clogging things up. None of my guys who did time in Afghanistan reported anything particularly different to me about conditions there.

            People keep harping on the M16’s failure to function under poor conditions. I simply haven’t seen it, except with regards to blanks that are generally filled with utter crap powder.

            I will say that running an M16 on whatever Radway Green was putting into their 5.56 back in the 1990s was a fool’s game; that stuff was, I think, filthier than the blanks we issued. That being said, if you liberally doused the M16 with Break-Free, as in “dripping out of the mechanism” drenched, they ran just fine. Although, what came off the weapon looked about like the oil you drained out of a diesel engine that hadn’t had a change in about 10,000 miles…

          • Kirk,
            I’m in the Mojave now, and found the Afghan dust coarser / less invasive than either our local sand, or the talcum-powder-fine stuff in the Euphrates valley. Of course, Afghanistan is a very diverse environment, and I only have experience in a few areas of the country.

            I used to think the ejection-port dustcover was just a “Good Idea Fairy” gizmo inflicted on the M-16 by bureaucracy (I still feel that way about the forward assist), but there’s a lot to be said for keeping the outside world outside.

            I try to avoid crap surplus in general, but thanks for the heads-up on Radway Green!

          • @ Mike,

            ‘Tis truly a thing of wonder, how military service can turn one into a connoisseur of prosaic things like the very dust of the earth.

            Although, I do have to grant you that there are limits to one’s experiences; what you encounter in one part of a region ‘taint necessarily typical for all of it. The fine dust you find at the NTC in areas where there’s been tons of historic traffic is something quite different than that where you’re just out driving around in Death Valley. I presume the difference between the two sides of the intervening mountain range has a lot to do with the amount of traffic beating on the roads and trails, preventing the build-up of that crust that forms on the surface every spring after the moisture evaporates. Either that, or there is a difference between the soils on the one side from the other…

            I’ll tell you one damn thing: The Mojave is the only place I’ve observed dust behaving like water, in terms of flow. There’s also the electrostatic light effects with that stuff that’s qualitatively different than anywhere else I’ve been; at night, under the right conditions? Holy mother of light shows…

            I will have to admit that you can do a hell of a lot to an M16 with dust and water combined, assuming you didn’t lube the ever-lovin’ out of it before it got wet. One of the players while I was there got caught out in a flash-flood that resulted in losing entire trucks and damn near washed away an M1 tank. Weapons were lost in all the confusion, some never being found. One of the other Observer/Controllers found an M4 sticking out of the side of a pile of brush in a wadi downstream during the next rotation, and I got to handle that poor thing. You think that dust is bad by itself? Add water, let it dry out inside a mechanism… Swear to God, I think you could have done less damage with concrete. You literally could not get anything to move until that carbine was soaked down in one of the tanks down at the maintenance section–Even the buffer tube was filled with hardened packed dust to the point where you couldn’t free anything up at all.

            I wouldn’t call that “operation under adverse conditions”, however. More like “operation under extreme and unusual to the point of ridicule”.

          • Kirk,
            Your first line was hilarious. I was thinking along very similar lines – “You know you’re a veteran when you have taste in sand” – while I typed my response!

            As to your next paragraph, I live on the leeward / east / gritty side of the Mojave, but I’ve been back and forth to San Diego so many times that I’m well acquainted with the other.

            Your “ridicule” remark really resonates too. Online commenters love to troll with comments along the lines of “Nuh-uh! Your ‘reliable’ [fill-in-the-blank] is useless against a mixture of 40-grit alumina and tabletop epoxy!” I’ve also read reports (Here? Not sure anymore) of government weapons trials using actual cement.

          • @Mike,

            Yeah, some of the online commentators can get very annoying with the sheer nuttiness of their conditions. Should you manage to build a weapon to endure those conditions, it’d likely be heavier than you could comfortably move with an entire crew and a small forklift…

            I have to admit that I bought into the ordure heaped upon the M16 for a long, long time. Then, I noticed how mine actually performed with live ammo, vs. the M200 blanks we normally fed the poor things. Live ammo? Nearly pristine weapon; I lent out a rack of them from my Arms Room to go over and do live fire for the ROTC camp, and I know for a fact that those weapons weren’t ever cleaned the entire time they were over there, and probably fired at least 5,000-10,000 rounds apiece while they were over there. No issues with them not running, at all–Although, it did look like the Exxon Valdez had visited my Arms Room after they dropped the rack back off. As you might suspect from my winning personality, words were exchanged between myself, my chain of command, and the assholes that’d signed for the weapons. I was not a happy camper–But, I did notice one thing: Wet, well-lubricated M16 rifles don’t seem to have much issue with working under adverse conditions. If I remember right, the cadre running that range for ROTC had been wont to dump a squirt of Break-Free into the action with every firing order, and when I say “squirt”, I mean from one of the big bottles they normally issue out for cleaning artillery tubes. Once we got some solvent into those weapons, they cleaned right up…

            I think one of the issues with the M16 stems from people over-doing the cleaning and the worries about dirt/dust. You go bare-minimum on the lubricant, and then try to keep it dry and clean-room immaculate? It ain’t going to work. The M16 is a filthy, dirty whore of a weapon, and loves to be run wet and nasty. Treat them with too much diligent care, and you’re almost certain to have more problems than if they’re leaving oil stains behind every time you set them down somewhere for more than a minute or two…

            Or, so I’ve observed. Looking back on it, I think most of my early issues with the damn things came because I was diligently following the advice of all those around me, and doling out the lube with an eyedropper. I’d like to go back in time and try running things a little differently, because I suspect that a lot of my results would have been different.

            Another thing about lubes… You do not want to run anything full-auto like an M60 or M240 on Break-Free alone. Those things really require something with some more stickyness and viscosity, like LSA. If it runs off the weapon in normal conditions, it’s probably not thick enough. The M16 delights in that thin stuff, and Break-Free is just fine for lubing them up, but the machineguns need more.

          • Kirk,
            Thank you for your wit and wisdom, which brought a combination of nostalgia, laughter, and note-taking!

            Since I try to remain solvent (and married) my only private-sector foray into the NFA world is (don’t laugh!) an M-11/9, but what you wrote about lubricants for FA makes a lot of sense.

      • I was unable to find a complete report.
        And I suspect that it will not appear in the public domain soon.
        If it ever appears… 😉
        But something about its results can be found on the net without much difficulty, as well as any kind of discussion.
        All this is interesting and informative, but (like any material from the network) is rather speculative interest.
        But the reality is that when the Israeli tankers replaced Galilons with Mekutsars, there was no limit to discontent.
        The mentioned situation with functioning failures has become commonplace.
        Of course, Mekutsar is not an M4A1, but if there is a difference, it is not fundamental.

        PS M4(A1) is one of my favorites.

  12. I was a Small Arms Repairman in the 126th Maintenance Btln. Which was part of the 4th Armored Division and we had the M-3’s. The only real problem we had with them was the spring that kept the barrel from turning. The tankers would bend or break them with some regularity. I guess that when you are dealing with stuff built for tanks, something as light as a sub machine gun can seem fragile.

  13. Well, I am a fan of Michael Heidler’s writings, but it is incorrect for Ian to say that there has not previously been “a significant book” on the Grease Gun. I think an apology is due to Frank Iannamico, whose own book, The U.S. M3-M3A1 Submachine Gun, published over 20 years ago by Moose Lake, is an excellent reference and certainly not insignificant.


  14. Very interesting book. I love reading about weapons and its history. Once I was even given the task to write an essay on this topic. I decided to go to the site and chose the section on weapon control. I think this is a very important topic in the modern world.

  15. I purchased a Semi-Auto version of the M3 from from a gunsmith named Valerie in Washington a number of years ago. She said that only approximately 150 were produced.
    Since the originals did not have a semi-auto mode they are not totally original but she did a excellent job of reproducing the external components. Shoots Nice.

Leave a Reply

Your email address will not be published.