Semiauto Madsen LMG Video

The Madsen light machine gun is note-worthy for several reasons – it was the first military-issue light machine gun developed and it was successful enough to remain in production into the 1950s (long after every WWI-era machine gun was long out of production). It was also one of the most usual machine gun mechanisms ever successfully designed – one of the early “what if we try this?” sorts of mechanisms that actually worked quite well. You probably saw the video of me running a Madsen in a 2-gun match last week, and the reason I actually had the gun on hand was to do a more academic video on its history and function. So if you have always been confused about that the heck is going on inside that mechanism, grab a cup of coffee and let me walk you through it:

FYI, my mistake in the tripod shooting was that I mounted the barrel support backwards. It has a spring assist built in to dampen recoil, but it only works one way. I should have noticed the big engraved arrow directing which way to mount it, but I didn’t (whoops).

We have a bunch of documentation on the Madsen on the Madsen LMG page in the Vault, which you should take a look at if you would like to read more.

Since I know people will mention it, the most recent use of Madsens in an organized combat capacity is with Brazilian police in Rio de Janeiro. There are a couple clips of them on YouTube (I’ve downloaded copies of these, so if they ever disappear from the web I can upload them myself). I take no responsibility for the cheesy background music, though:


  1. Great Video! I sold a couple of ARs to buy my own Portuguese 1950 Madsen. They are surprisingly accurate. The 1950 bipod is much steadier.

  2. Ian, do you make a distinction between “automatic rifles” and light machine guns? The reason I ask is because the BAR was in production into the 1950s, as far as I know.

    • True, although the BAR was a decade and a half behind the Madsen in terms of production start, and Browning was able to learn from the other light automatic rifles like the Lewis, Madsen, Chauchat, etc in developing the BAR. It’s the combination of being the very first reasonably successful attempt at the concept plus being in production and use for so long that makes the Madsen so impressive to me.

      The distinction between automatic rifles and light machine guns is a tricky one. I think the problem is that the dedicated automatic rifle as a concept didn’t really work all that well, and its job would up being split between the rifle and the light machine gun or the GPMG, and there are not many real “automatic rifles” as the term was originally envisioned. But the technical defining characteristics tend to match up to light machine guns pretty well. Off the top of my head, the only two automatic rifles that come to mind are the BAR and Chauchat, and they were both elbowed into LMG use instead when people realized how ineffective walking fire turned out to be.

  3. I think yours has a sight mount on the left side of the lower receiver, just above the rear end of the trigger guard. Good luck finding the sight; I *think* it was a fancy non-telescopic sight for use mostly from the tripod, probably for long-range indirect fire. If you know a friendly machinist, though, you could make a scope mount, heh.

    Monopods, which have that same double-screw adjusting system as the tripod, have been available from Numrich and IMA from time to time.

    • Yep. I haven’t ever seen an original optic, but Bob Faris had a full-auto one that he modified a Russian PSO scope onto using that mounting point. The owner of the semiauto gun I used in the video does have a rear monopod for it.

    • The rail on the left side of grip is for a clinometer (I was lucky to found one, the seller has no idea what it is for), to use in indirect fire role. The clinometer (after set by officer) slide on the gun to check if the gun is set at correct angle and remove before firing.

  4. Geeezus H. & Mary Christ… Using LPG tank rack as a barricade … Then firing from under the electric transformer containing several gallons of oil, waiting for a match…
    I’m not enough in Superman mode to be a Brazilian Police BOPE member. Thank you just the same

    • Leszek, while you have a good point about the folly of taking up a firing position underneath a mains electrical transformer, the real danger if that transformer is hit by gunfire or otherwise damaged lies not in the contents of the oil bath ( modern transformer oil baths are usually non-flammable or at least non-volatile ) but in the fact that a damaged live transformer will typically arc-flash in a violent manner due to the sudden short-circuiting of the existing electrical load. This often takes the form of a powerful high-voltage, high-amperage energy surge and release or explosion that can send off electrical arcs ( following the path of least resistance, whether it be a conductive pathway such as a grounding loop, an atmospheric anomaly in the immediate vicinity, a human body in contact with that pathway, etc. ) in different directions that will cause serious injury or death to anyone unfortunate enough to be struck.

      • Yeah – anyway, not a good choice of firing position, and that was what I pointed to. But thanks for explaining the different nature of the risks involved 🙂

        • Yeah, if you understand portuguese, the police officers themselves point out that the drug dealers might hit the transformer and that they should move out of there.

          Guess that street was important and had to be guarded. Also, from the side view, there isnt much cover besides that wall over there.

  5. OMG! Was this mechanism designed by an undergraduate on an LSD trip?
    And yet it worked! I recall a comment in one of Ian Hogg’s books that making this thing
    work with a belt feed was like operating 2 elevators in a single shaft. Now, I am not a mechanical engineer, so can anyone explain?
    Oh, Madsen also produced a prewar 23mm AA and aircraft gun. Did it use the same crazy but reliable
    mechanism? Why 23mm? Any connection with the later Soviet Nudelman cannons?


    • The 20mm and 23mm guns used the exact same mechanism scaled up to fit the much larger cartridges.
      The 23mm was made by necking out the 20x120mm Madsen cartridge.

    • I have photos on the Vault page of a belt-fed version – I ran across a parts kit for one at a gun show not too long ago. The wacky thing with the belt-fed versions (at least the one I saw) was that one of the feed pawls was built into the belt box rather than the gun. So if you didn’t have the belt box clipped on, the feed mechanism wouldn’t work. In addition, they needed a way to get rid of the links (it used a disintegrating link belt), and the method that they came up with was a horseshoe-shaped tunnel running up and over the receiver before dumping the links on the right side of the gun.

      • True – using beltbox to transfer belt is odd, but at the same time the Webley Scott pistols (and Polish PM-63 machine pistol) used a projection of the magazine lip for an ejector, which is kindred in a spirit at least, if not in actual role of the cartridge receptacle for a vital role in gun functioning.

  6. Cheers Ian!

    I’m full of admiration for anyone who can come up with a crazy mechanism like this and make it work. From what you said in the YouTube comments, it seems like all it really needs is a “forward-assist” of some sort to make it a truly sound design.

  7. Pretty sure the RPK is an automatic rifle and not a light machine gun. That has been reasonably successful concept in a very limited feild. Not sure how you would define the new PKM (PKP Pecheneg)?

    • Mike: I think the new PKP Pecheneg can still be classified as a LMG, but a borderline one for sure, as it lost its predecessor quick-change barrel feature… The barrel of the Pecheneg, on the other hand, and despite being shorter than that of the PKM, is said to be heavier. A trade-off, really. Anyway, the Pecheneg is not meant to replace the PKM. It is intended tactical role, it certainly is an improvement over the RPK-74.

      • Sorry, I should have written “In its intended tactical role” and not “It is intended role”…

    • Name RPK – ruchnyi (hand-held) pulemyot kalashnikova captures the role of it pretty well, I’d think. Let’s not forget, lots of mixup in terminology is crated in excessive marketing drives by makers. They feel that by tossing new term in place they actually create new product. Some part of it is also on behalf of procurement.

      My own definition would be: does it shoot primarily full auto? Does it do so from open bolt? If yes, its MG. Let everyone to make up their mind.

  8. Can you remove a half empty magazine from the gun without losing a couple of rounds before the ‘feed lip’ on the mag catches the rounds?

    • Once the gun has started drawing ammo from the magazine, if you remove the magazine before it’s empty, you’ll have to deal with 2-3 rounds: one in the chamber, and one or two working their way towards the chamber through the works. You can usually finagle one out the top of the magazine opening, but it’s easier to just fire them down-range.

      It’s a chore when they sound the cease-fire at a public range, though; plus the local range wants the range safety officers to be able to see into the chamber (more or less) when they come by. I usually end up halfway-disassembling the gun …

        • Headspace is not field-adjustable. The barrel is threaded into the breech assembly, so headspacing would be done at the factory of by an armorer’s shop equipped to replace barrels. Once the barrel/breech assembly is put together, it includes all the parts relevant to headspace, so it’s not a matter of concern when swapping out assemblies in the field.

          • The easy way to explain a Madsen at the range: “It’s a Martini rifle, living inside another, larger weapon.”

  9. Thickly effing rough-hide cops know their territory (or favelas to say it in their tongue), that’s for sure. This is kind of action I would not mind applied in some portions of drug infested sections of Toronto. It would need to be done just once.

    However, back to the technology; I am not sure what REAL effect that Madsen had part of making impression. In my mind it should be one shot – one man down. After all, there are plenty of innocent folks around. Pistols and some odd carbine would suffice. You can clearly see that over-equipper cops have actually kick out of it.

    On note of usage of vintage guns (and thanks to FW crew’s courage we see them working as they are intended to) I could not help couple of times to think of safety. Those old hoses may have developed micro-cracks in critical areas and on top of it, the current super-duper ammo is probably hotter than that they were designed for. Any ideas on that?

  10. Thanks Ian. I finally understand how the Madsen works. Except for one thing. Is the breech closed on a live cartridge, in what would be a closed bolt fashion in a conventional rifle? That is how it looks. Was there any problem with cook-offs with high volume firing?

    • Yes, the Madsen is a closed-bolt design. I’m sure it would eventually cook off (all closed-bolt guns can), but the barrel is fairly heavy and it was possible to change barrel assemblies if a heavy volume of fire was anticipated.

  11. To add one more to Denny’s comments : Is it belt-fed rather than magazine-fed? Although there are some LMG’s that are magazine-fed, there are very few, if any, automatic rifles that are belt-fed. This characteristic will obviously have to be used not as a stand-alone definition but instead in conjunction with the other typical characteristics listed when defining a weapon’s role or status.

    The line between the LMG and the automatic rifle is sometimes thin and not a little blurry. The open bolt versus the closed bolt characteristic may work as a defining point if used in conjunction with the other defining characteristics, but not solely in itself, since there are several true MG’s that fire from the closed bolt, eg., the Browning M1919 .30-caliber MMG and the Browning M2HB .50-caliber HMG.

    • Well Earl, yes you have a point there.

      As you may know, during my (so far) lifetime and thru my experience I came into contact with several genres of terminologies. Without going too deep into linguistics (and in due respect to universally acknowledged benefits of English language) we can also say that the terminology gets pretty fuzzy at times. For that reason and more than just inadequate hearing you hear people saying: “…how did you mean it?”. So this particular language we use is not exactly descriptive either. As a sample lets look at word “gun”. What is it actually? In comparison, perhaps German would come bit closer – you have pistole, gewehr (buchse), machinen-gewehr, kanon and so forth.

      I perhaps will not stray too far from essence, saying that while the terminology was created in past for different sorts of armaments, it has established itself on some kind of, then accepted standard. I’d propose therefore to call things of historical significance by the names as they were assigned, regardless as what they would be called today if new.

      So, for instance Browning heavy(automatic) rifle (sound&trusted) would remain just that, although it had been frequently used as “light support weapon”. More current LSW being M249 (POS by some accounts) is in fact less than successful attempt for LMG. Some mentioned Pecheneg as typical full-value LMG and I’d certainly concur.

      • Denny, if we use your terminology of auto vs machine – would that mean that the RPD is a machinegun (open bolt), while Maxim 08/15 is an automatic rifle by virtue of closed bolt? You don’t seem to be a dyed-in-the-wool fan of the ancient machineguns it seems: most pre-WW1 machineguns were firing from a closed bolt (Lewis and Hotchkiss being notable exceptions to the rule). You can’t devise a universal, all-cases-covered definitione, there will always be exceptions. Generations of theoreticians tried that Magic-Bullet approach and their theories simply held no water. The human being is a damn devious, mischievous creature, that you can always count on to devise something that would derail any “100% Sure System”.
        The Russian term of “Hand-Held Machinegun” (also Polish and Czech for that matter) is in fact a face-saving attempt at translation of the almost non-translatable French term of Fusil-Mitrailler (literally a Rifle-Machinegun), which the English translated as Machine Rifle but now sadly discarded entirely. This term (Machine Rifle) would be covering the “magazine-fed, FA with optional SA, bipod fired automatics” which encompasses nicely most firearms like Madsen, Lewis, Bren, RPK, MG 13, BAR etc. leaving the LMG term where it originated – for bipod fired beltfeds (08/15, Hotchkiss Portatif, RPD, Minimi, MG 34 and 42 in light role, MAG, PKM and the likes of them. Without it, the bloody Englishers have put a seed of chaos into machine gun classification, dividing them into Machineguns (mounted) and Light Machineguns (not mounted, regardless of any other distinction) which lead to having the likes of Maxim 08/15 (21 kg combat ready weight) and Enfield L86A1 or RPK-74 (ca. 5 kg in combat trim) in the same class of weaponry…

        • Its a mess Leszek, isn’t it? I am not trying to bring in any rules, because as you are correctly pointing out, there is hardly any base to them. And actually, I like those (close bolt fired) machineguns. I museum on Hradcany’s Square they have nice collection of them.
          some languages cope with terminology more consistent with true meaning (karabin-maszinowy) as opposed to ‘kulomet’ (ball-thrower).

          I’am taking too much space here, I better get out. Czesc!

        • Leszek, an excellent overview of the state of terminology.

          Let me add that we bloody Germans are basically in line with the “bloody Englishers.” But light machine gun does not sound bureaucratic enough for modern Bundeswehr, so we call it “machine gun on bipod” (Maschinengewehr auf Zweibein) nowadays (introduced 1972). But it remains the same for MG 08/15 as well as RPK 74 as you say. Maschinengewehr is literally machine rifle as you know.

          In WW1 for lack of a name the Russian Madsens used by German troops were called muskets.

  12. The rail on the left side of grip is for a clinometer, to use in indirect fire role. The clinometer doesn’t stay on the gun during fire, just slide on the gun to check if the gun is set at correct angle before firing.

  13. The barrel change feature was actually used in the danish army, each recoil rifle squad being issued with two spare barrels and water bags for cooling the barrel.
    Last model used by the danes was the M/48.

  14. Any “deal killer” aspects of the Madsen? Would you rank it as equivalent in reliability to modern MGs, or better or lacking? Do you think that a military armed with Madsens (given logistical support) would be more poorly armed than one armed with BARs? If so, why?

    Basically, do you think the Madsen is just good for the time or actually really competitive even vs. modern MGs?

    • The downside of Madsen is, if you only have poorly manufactured, lower power rounds, the Madsen would not work, on the other hand, gas power MG can adjust to shoot low powered rounds.

      Extracting a unspent round is also very difficult, and it might lead to jam.

    • As good as the Madsen is, it isn’t equal to the later designs. The Bren is better, for one, and the later FN models of the BAR would give the Madsen a good run for its money as well. I’d say the negative aspects of the Madsen are clumsy handling (by today’s standards), and poor ability to clear malfunctions (although this is mitigated by it being a pretty reliable action as long as your ammo is decent).

      Given trained crews, forces with BARs and Madsen would probably not see any difference in effectiveness on account of the guns, but my preference would be for the Madsen.

  15. The Madsen does need good quality ammo for reliable function. However to properly clear a jam it is best to remove mag first then pull the loose rounds in feedway out with fingers THEN yank the operating handle back. Not as easy as immediate action drill,but it works.
    BTW,the first Madsen LMG seemed to be “closed bolt” type but were later modified to work as “open bolt” to prevent cook offs/provide better cooling.
    The semi auto copies are set up to fire “closed bolt” to satisfy legal requirments of the BATF.
    The semi auto rebuilds are much fun to shoot and can be had for about $3500 US. Built by Midwest Metal Creations they run like a top.Have had one for a few years and it works very well with good quality suplus ammo. Only trouble was with Turkish Surplus.
    Moral is,do not run cheap ammo in expensive gun !
    IMHO a LMG is a MG a man can pick up and fire without giving himself a hernia.

    • Actually, the semiauto guns from Midwest are only $2500 – I talked to Dennis while putting together my video. Really a pretty good deal for an interesting and well-made gun.

  16. Reading once again through all the detailed and highly-knowledgeable commentary that has been posted, I have come to realize that one important thing still stands out — the fact that, in spite of its unorthodox design, mechanical complication and occasional eccentricities, the Madsen is still a machine gun that is the sum of its parts, a sum that happens to work rather well.

    Also, for uniqueness and sheer panache, there are few guns quite like a Madsen LMG.

  17. ..I have two Madsens, both built semi-auto by Denny at Midwest Metal. Both run very well but ammo is the key. I shoot Turkeys finest 1940’s issue but check every round before loading it. Somebody asked about downsides. It is a cam lever nightmare inside. Replacing the barrel is possible, but you have to have 3 hands and everything has to be lined up EXACTLY in the right position before the barrel slides in and the gun can be closed and locked. Anything else jams the barrel part way in.
    …If you have the desire, pick up the Danish DVD ” 9 April ” which details one squad of a Danish bicycle infantry unit that fought. The Germans won in 6 hours, but it shows the Madsen LMG and the Anti-Tank 20mm in action against the krauts. A region 2 ( Europe ) DVD and it’s subtitled , but no in English. At the end of the film they interview the last living members depicted in the movie.

  18. …The Madsen LMG suffers from a safety flaw common to early machine guns: you can’t tell if it’s loaded or clear without opening it up and looking. So does the Browning, Maxim and Vickers. Oh, you can cycle the action without a feeding device until you are pretty sure, but you’ll have to open the top cover of the Madsen to look in and see if a cartridge rim is sticking out of the breech. Likewise, on the Maxim designs you hang the lock and the Marines figured out a device ( T-block ) to insert into the open action of a Browning that tells everyone it’s really unloaded and safe.
    …Amazon now claims to sell a copy of the Movie 9.April with English subtitles. Still region two; European. Won’t play on a US DVD player. The industry set this up intentionally, the bastards. I ordered one and will post the results.

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