Yugoslav M72: The Early Balkan RPK

When the Yugoslav Peoples’ Army began AK development, they produced the M64 infantry rifle and the M65 support weapon. The M65 had a longer and heavier profile barrel and a bipod – and in its very early experimental iterations a quick-change barrel mechanism and a folding carry handle. By the time it entered regular service it was the M72, the carry handle was gone, and the barrel was fixed in place.

The internal parts of the M72 were interchangeable with the standard M70 rifles, and they could also use the same magazines – although a drum was made specifically for the M72 to allow more sustained fire. Note that like the M70, the M72 originally had an automatic hold-open for empty magazines, but this was removed to allow compatibility with standard AK pattern magazines. The original M72 used a distinctively shaped milled receiver like the very first M70 rifles. Two later versions would follow; the M72B (slab-side milled receiver and pinned barrel) and M72B1 (stamped receiver).

Thanks to Polenar Tactical for arranging access for me to film this excellent example of an early M72!


  1. [OFF-TOPIC so ignore if you wish]
    I recently become aware of new cartridge named 360 Buckhammer.
    Remington (manufacturer) claims it is launching 200 gr at muzzle velocity equal 2200 fps.
    It was spawned by .30-30 cartridge, which itself was spawned .38-55 cartridge and https://www.buffalobore.com/index.php?l=product_detail&p=159 claims that modern loading for .38-55 does launch 255 gr at 1950 fps, so 2200 fps with lighter bullet seems feasible to achieve.
    Is Buckhammer name of its’ designer, if not what does it mean? Why new cartridge was created when it achieve what older should be able to do? Does 360 Buckhammer operate at such high pressures that it was found undesired to make it compatible with older rifles?

    • Buck: usual American term for stag / male deer
      Hammer: common nickname for a powerful, hard-hitting fighter

      Its advertised purpose is medium / large-game hunting in states that have straight-wall cartridge requirements. You’re right that it doesn’t do much of anything pre-existing cartridges couldn’t do, but it exists for the same reason as many products: to sell stuff to people who want the new or different thing.

    • 358 dia bullet operates at 30-30 pressure levels.
      It’s desighn goal to meet the restrictions on ammo you can use to deer hunt with in certain areas. That is it’s reason for being , same for the 350 legend .

  2. I still question the value of these upchunked individual weapons. If the thing ain’t got a belt feed and a swappable barrel, it’s not a support weapon, and there’s nothing you can really do to change that fact. BREN notwithstanding…

    The caliber is also another consideration. What do you really gain with using the same lightweight caliber that you can put into your individual weapon and have your riflemen still be able to shoot it on fully automatic?

    I have to question the entire premise, to be honest. I do not think these things are at all useful, and I have to blame the same long list of idjit types that brought us the BAR and all the rest of the “walking fire” line of weapons. You ain’t effectively firing a fully-automatic weapon on the move; if you need to support your movement with fires, then you need to be able to dominate the firefight, and you’re not doing that with anything off the bipod and with a mere magazine. You need belt-fed, and the ability to transition to the tripod with its locked-down fire control capability.

    You don’t see a lot of people actually lugging these things around, if they’ve got a choice and have some slight experience of modern combat. The RPK niche is one that you don’t really need filled, TBH.

    At least, that’s my humble opinion. I’d prefer a light and highly mobile belt fed, in a caliber that can contend with light material targets, on a mounting system that I can effectively use to control fires from. That last bit? That’s really the important one; with a guy shooting a MG off a bipod, about all you can do for fire correction is “Yeah, up and to the left, a bit…”. With a tripod? “Up 10 mils, left 25 mils”; you can quantify things succintly and accurately, which effectively doubles or trebles the effects of your shooting.

    Not to mention the morale impact on the enemy, when the MG they’re facing just keeps dropping them like flies with very little actual fires coming their way. The thing that does it is the apparently infallible accuracy and precision; you get the feeling that you can’t safely do squat, while that MG team is out there dropping rounds on your ass every time you try to move.

    • Given the Brits carried the BREN into the Falklands, there has to be something to the concept of a mag fed LMG, and the Japanese used it rather effectively as well. Our own Marines have just adopted an external-piston AR in the automatic rifleman role & parked their belt-fed M249s, so some folks see value in it.

      The Marines are never happy w/ their issued rifle, I’ll grant, but they’re actually willing to take casualties unlike our Army, which I rather respect.

      • The fact that the Brits took the BREN into the Falklands is more a function of them refusing to properly address the fact that their supposed “General Purpose” MG was too heavy to be fit-for-purpose than it is a sign of any advantage or superiority of the magazine-fed weapon. It’s also an indicator that the FAL wasn’t all that it needed to be, in terms of how much firepower it could generate at the squad level. Reality was, the FAL wasn’t all that much of an improvement over the SMLE.

        The Marine choice for the M27 is one they’ve made for themselves. I rather hope they can make it work. I personally think that it is based on a flawed set of assumptions and conceptions about the nature of modern combat.

        The Marine ideation is that speed of maneuver trumps everything else in combat. They feel “encumbered” even by the relatively lightweight M249, which they never bothered to maintain or support properly, resulting in the horrid reputation that it got for reliability among their infantrymen. The idea can be summed up as “We’uns gonna go dancing in between the bullets…”, which I happen to think is totally asinine. The problem with it all is that it’s essentially a pointless activity; your maneuver is supposed to be gaining you a positional advantage for your firepower. That said, it’s an act of utter stupidity not to take that firepower with you while you maneuver. Sure, you got into that position swiftly enough, but once you’re there and attracting the fires and counter-attacks? What then? Also, what the hell are you going to do, with essentially just the stuff you carried on the assault? Are you going to be able to influence the battle, at all? What’s the damn point of all that maneuver, if you’re just going to sit there waiting for something to come drive you back out of those positions, without holding them?

        You can’t predict when and where you’re going to need the things your belt-fed weapons provide; you don’t have them with you? You’re wasting your damn time with that maneuvering. You can certainly choose to rely on your radios to call in for fires, but I’m not a fan of that whole school of thought in force-on-force combat. If you’re going to try to reduce warfare down to getting your FO around the battlefield and protecting them, well… That’s a technique, but I think it’s one that is going to be getting a bunch of people killed, because once their comms are suppressed, those FOs are basically just heavily-laden infantry without much more than their sidearms.

        You can fight like that, but I’m not going to be signing on to join you in what I consider your folly. Comms-reliant warfare is not my preferred path.

        • “(…)Reality was, the FAL wasn’t all that much of an improvement over the SMLE.(…)”
          Wait… are you just claiming that full-auto weapon with default capacity 20 does not give noticeable advantage over 4 movements repeating rifle with capacity 10?
          That is… extraordinary claim, so I suspect you have bold evidence for that.

          • L1A1 was never issued in a full-auto configuration.

            Effectively, the rate of fire that you could generate with one was really not all that much better than a well-trained rifleman with an SMLE could. Which was why the BREN was still a necessary thing, down at the squad level, especially considering how heavy and unwieldly the L7 GPMG was.

            It isn’t a question, necessarily, of the L1A1 being better or worse than an SMLE at generating the necessary firepower to dominate the firefight; it’s the fact that you were matching it with the AK weapons complex, and that was where it got badly hurt. Had the L1A1 ever gone into heavy action like the M-14 did in Vietnam, it would have showed its ass in a similar manner. There are reasons the Israelis shed themselves of the FAL as quickly as they could.

            The Falklands are something of a red herring, anyway; the Argentines had equipped themselves with metric FALs that were equipped with full-auto capability. Being as they were the same uselessly heavy caliber in an individual weapon, they offered up no advantage, and with the better-trained British infantrymen carrying the L1A1, the results were what they were.

            Every time we’ve done this dance, the end of the day has everyone with an intermediate-caliber individual weapon (AK, M16, Galil/Tavor) and a full-caliber support weapon (PKM, M-60, GPMG/MAG-58). Nobody who had a damn choice stuck with the old-school magazine-fed support weapons that were really just a halfway house carried over from ye olden dayes.

            In short, yes the L1A1 is marginally superior to the SMLE. It remains markedly inferior to any real intermediate-caliber individual weapon like the AK, the M16, or really anything else of that ilk.

            And, yes… I own one, in the guise of an FN metric model, but the sad reality is that it’s not a weapon I’d want to take to war. Range toy, historical-interest item? Absolutely. Tell me people are gonna be shooting at me? Oh, hell no…

          • “(…)L1A1 was never issued in a full-auto configuration(…)”
            Then this is entirely different claims, as it pertains weapon spawned by FAL, but itself not being FAL (unless I catastrophically misunderstand 2nd letter of that name).

          • When you speak of the FAL in British service, it’s the L1A1, notwithstanding the odd trophied metric FAL they pressed into service somewhere.

    • “(…)What do you really gain with using the same lightweight caliber that you can put into your individual weapon and have your riflemen still be able to shoot it on fully automatic?(…)”
      Ability to carry examples of ammunition. Please be warned that 7,62×39 cartridge was developed with following must have https://weaponland.ru/board/patron_762x39/43-1-0-225
      энергия пули на дальности 1000 м должна была быть не менее 25 кгм
      Unlike Kurzpatrone, Soviet one was designed to be used in trio of weapons: carbine, automaton and hand-held machine gun and therefore make effective up to 1000 meters (above shown energy was considered to make it lethal enough)

      • Whatever they initially intended, they still wound up supplementing the 7.62X39 with the PK/PKM in 7.62X54R.

        That’s how it’s always worked out, since the end of WWII. Theories abound, but once you start shooting, there ya go: Dual calibers in the squad, no matter what happy horseshit the theorists came up with. NGSW will wind up working the same, although it’s possible that they might wind up having the Chinese solution of the same case, different loadings for the machineguns…

        • I didn’t remember the Chinese doing that, but I’ve come to wonder whether that might be an effective “cheat” (given that belted and boxed are different DODICs / NALCs anyway) to obtain most of the advantages on both sides. I’d spec a different OAL for the LMG, which could then use rifle cartridges in a pinch (but not the other way around).

          • It’s not the path I’d choose, TBH.

            Ideally, anything that you can fire and still be able to control in an individual weapon is inherently going to be incapable of being pumped up enough to really do well as a support weapon. You could take the approach of downloading a support weapon cartridge, but then you’re not going to save all that much on weight or size of the cartridge.

            Horses for courses, say I. If I were setting about the design of a “squad weapons complex”, I’d first set out what the hell I wanted them to be able to do. A polyvalent “do anything tasked” squad needs easily carried and flexibly wieldable individual weapons they can fire and control on full automatic; this means a cartridge somewhere slightly south of the old 6mm SAW. They also need a support MG that can reliably take out light vehicles and personnel targets out to around the 1500-2000m range, direct-fire. Supplementing that, they need a versatile direct-fire AT/Anti-Fortification weapon about like the Carl Gustav M4, and a grenade indirect-fire projector of some sort, like the various 40-60mm options. You could do well to procure both something like the 40mm grenade, and the French LGI F1 51mm mortar.

            Either way you look at it, the basic issue is that you just can’t hit both sets of requirements with one cartridge, or even one set of interchangeable cartridge envelopes. Trying to square that circle is a fool’s game.

          • As an aside…

            One of the things that you note when reading history is how little actual “learning behavior” is demonstrated by the mass of humanity.

            Frankly, I find it scary. Especially in a military context. One should never, ever approach any situation with a fixed set of ideas about anything. One should, instead, follow the Boyd Loop: Observe, Orient, Decide, Act.

            You have to be objective and brutally honest with yourself at all stages: Is what you’re doing actually working? If not, why not? If yes, analyze why. Then, orient on a solution or continuation of your initial action, determine how to move forward, and act on that determination.

            Applied to small arms? You need to be aware of what’s going on, out there on the battlefield. This is one reason I’m so cynical about much of our efforts; there’s apparently been little real effort to observe and understand. Instead, rather than actually gathering the data, we rely on purely subjective observations garnered from really unreliable sources. PFC Snuffleupagus may be a perfect candidate as an informant for how best to turn combat rations into something palatable, but when it comes to small arms? Does the little toad even understand the most basic principles of mechanics or ballistics? Is he a reliable and consistent observer, or is he someone who parrots the opinions he’s heard around the water cooler equivalent?

            I’m here to tell you that I really doubt we have even a first f*cking clue about what effects we’re actually generating downrange. All we know are subjective things, like “Yeah, we fired that new toy at the enemy, and they fled…” OK, great: WHY did they flee? Was it the new and unusual signature? Was it because they ran out of ammo? Did they actually just act out of pure self-interest for entirely unrelated reasons?

            There’s so much magical thinking in this arena that it’s not even funny; few things are quantified, because they’re hard to gather the data for. Which, I fear, is a mistake. Forensic examination of the various battlefields is something we ought to be doing, right down to full-scale autopsies of enemy remains. Did those guys die due to our weapons effects, or was it sheer accident?

            About the only thing I’ll go on record about is the unreliability of eyewitness reports. Dude tells you “Yeah, that weapon worked…”, that’s an automatic reject, information-wise. You can’t tell; all he knows is that narrow slice of the battlefield and the action that he observed. And, his observations are entirely suspect, in that he really doesn’t have a god’s-eye view of things. He can’t know what influenced the enemy to stop shooting at him; all he knows is that he fired his weapon in their general direction, and he ceased receiving incoming fire. The actual “why” of that? He’s utterly and rightfully oblivious. Why should he, as an individual, care?

            That’s the root problem with a lot of this crap. Nobody really has the data; I suspect that if we get it, a lot of the assumptions we’ve made will be shown to be utterly in error.

          • Regarding your second question, it’s hard to say which is worse – shallow PFC anecdotes, or bizarre abstractions from pundits like the one that led to NGSW.

            Like several recent procurement programs (DDG 1000, anyone?), NGSW had overreaching “requirements” that produced a questionable product, but with the beneficial side-effect of demonstrating several positive individual technologies. I think it’s quite possible to apply those to say a 6×45 cartridge that could “reach out and touch someone” with VLDs in an LMG, while at the same time it could easily be loaded to (or below, for PDWs) current 5.56 ballistics for rifles. Even 5.56 itself could have some reach and punch if freed from the constraints of AR mags (and given proper mount and optics).

          • The thing that just absolutely enrages me about a lot of the procurement process is that the idjits in charge treat everything as though they were procuring whatever it is as the absolute last best thing ever that we’ll ever need to be buying in that class of equipment.

            Look… Equipment wears out. We know this. Every object has a finite life. You know you’re eventually going to be replacing that item, even if it’s the damn rock you put around your headquarters flower bed. Why isn’t that ever accounted for?

            Hell, we knew the M-60 was at the end of its logical service life when I first enlisted, back at the beginning of the 1980s. Yet, nobody in the responsible agencies ever said “Y’know… Maybe we ought to start thinking about how we can improve the MG situation, when we finally have to buy new…”

            Which is precisely how the Marines and Rangers wound up leveraging us into the too-heavy M240. They really didn’t have a choice; it was either that, or the idjit class was going to recapitalize the MG fleet with more of the same POS M-60s. Which, frankly, never should have been procured in the first damn place, in the form that they were. It would have been fine, had someone said “Yeah, that’s a nice first attempt… Now, go get it ready to actually issue real troops…”

            As an aside… I loathe the M-60 as it was procured. I think, however, that the bare bones of the system could well have been turned into something a lot better than what I got handed as a PV1 gunner.

            The mentality that you saw on display with the ACR program is a perfect example: They wanted something like “100% improvement over the M16”. Seriously? Guys, the only way you get something like that is if you’ve got paradigm-busting technology in the pipeline like magazines, brass cartridges, and smokeless powder combined. I don’t think that even the Lebel represents a “100% improvement” over the older French rifles, unless you go back to the models before the magazine-fed Kropatscheks they issued colonial troops.

            So, they start with asinine goals, and end deciding that nothing is a significant enough improvement over the M16 to justify something new. Wasted money on the entire program; I think the only thing that came out of ACR was popularizing some of the stuff they later wrapped into the SOPMOD program.

            What should be going on is a continuous evolutionary process that keeps iterating improvements until we reach a point in the service life of what’s currently on-issue, whereupon we’ll recapitalize the fleet with that which is ready and waiting in the wings. The idea that we’re still issuing basically the same damn weapon (look at the TDP) we were back in the 1960s is ludicrous. They should have slipstreamed in modern technology all along the line–Better coatings, CHF barrels, functional night sights…

            Things soldiers actually, y’know… Need. The fact that we didn’t mass-issue effective night sights from Vietnam days forward is ludicrous; the damn Israelis and Finns managed to put effective, functional night sights on their AK-derivative basic rifles, yet we never did? Adding insult to injury, we basically paid the Israelis to build the Galil for themselves, while our guys were bumbling around night ranges unable to see the front sight posts on their brand-spanking-new M16A2s. In-f*cking-sane.

            We do procurement entirely wrong. Instead of going all blue-sky “best of the best of the best” every generation, usually under “crisis action management mode”, we ought to have a slow and steady evolutionary process always going on, evaluating new technologies and production processes as they come on line in industry. Additionally, someone needs to inject a note of reality into the process, because if you observe, the fact that the M16A2 in all of its guises has basically been totally supplanted by the ballistically inferior M4 carbine for all infantry use.

            That’s a clear sign that the idjit class who came up with the A2 got it completely wrong; the M4 was only ever supposed to be a weapon for guys who didn’t “need” the A2. What happened? Oh, yeah; as soon as the infantry saw the M4, they all glommed on to the damn things, flawed as they were, ‘cos “easier to carry”. Apparently, what the infantry really needed was a smaller, lighter M16, not the musket the idjits gave them.

            I’ve been all over the post-Vietnam After Action Reviews. Nowhere in any of those documents did I find anyone saying that the M16 was great, it just needed to be longer, heavier, have a more complicated sight system, and be capable of competing at the National Matches out of the box.

            Lots of stuff calling for lighter weight, better night sights, more durable stocks and handguards. The last two they did provide with the A2.

            You go and look at anything the US military does, and it’s the same sad tale of woe: We gotta blue-sky everything, to justify replacing it. I say we simply look at maintenance costs, recognize that sh*t wears out, and when it does…? Replace it with something better, rather than buying more of the same crap we had on issue fifty years ago.

            The fact that we don’t have CHF barrels on the basic TDP for the A2 is a sign that we clearly don’t know what the hell we’re doing, procurement-wise. If what I’ve read is true, they’ve finally gotten around to implementing them on the M4A1, but I won’t be holding my breath.

          • Kirk,
            I agree that an evolutionary process is required, but I’d add that the next thing need not be the next thing.

            Most industries see periods of revolutionary innovation, and periods of evolutionary iteration and optimization. The former captivate people who follow history of technology for “fun”; the latter produce the vast majority of effective, safe, and useful products. We’ve been in the latter regarding small arms for quite some time.

            Almost every new procurement program produces not only tremendous costs vs. continuing / restarting production lines, but also countless unforeseen issues that take years (sometimes decades) to debug. History is replete with militaries finding a few shortfalls and/or potential improvements and throwing the baby out with the bathwater to be replaced by a (sometimes worse) scratch-design. With very few exceptions (products in a period of revolutionary change and actual mission-related need for that change) every procurement program – once it has identified shortcomings in the current issue – should include an analysis of alternatives that includes an honest assessment of whether they can be corrected. While I agree with you on M4 vs. M16, the modern M16 program deserves a lot of credit for not wandering off into futurist / “because we can” la-la land.

          • Mike, I agree with a lot of what you are saying.

            I think the problem is that you have to be able to recognize when you’re in a steady-state set of affairs with regards to technological advancement, and a period of revolutionary change.

            The era when we were feeling our way though breech-loading and smokeless powder? Era of revolutionary change. The era after WWII? Not so much; that was a period where evolutionary incrementalism held sway. Or, should have; small arms were no longer changing significantly; we’d broken the code for a lot of the technology and all that was going to happen was minor incremental change.

            It’s a question of how you manage things; weapons in the small arms arena are no longer revolutionary-change items; they’re evolutionary. As such, they should be managed as expendable items, with finite lifespans. You know the rifles are good for, say, 50,000 rounds fired in training, somewhat less in combat. Because of that, you can say “Yeah, we need that many to equip the force; go ahead and procure them, they ought to last X number of years.” Then, with that information, you monitor the market and technological space to keep your “next in line” system ticking over in the procurement pipeline. Run a few batches of them when justified, for testing and production validation, then when the time comes, replace the old and worn out with the new and start up again.

            The thing that doesn’t work is this crazed deal where we buy once, and make believe that we’ll never, ever need to buy again, or that the market/technical space won’t have moved on since our last major purchase.

            I don’t think there’s going to be any “revolutionary” things in small arms until there’s a major set of innovations in materials or energetics, probably both. Until they can reliably seal a chamber for caseless without having to worry about gas erosion destroying the obturation? That pipe-dream ain’t happening. Same with gauss guns or linear accelerators–The energy densities for the batteries and capacitors ain’t there just yet. Maybe never will be.

            This being the case, the most likely thing for improved performances in the weapons down at the squad level are most likely to be found in target acquisition, sighting, and all the command/control/communication issues. The rifles are going to be mere clip-on accessories for the sighting systems in very short order; the synthetic reality tools aren’t going to care about what they’re attached to. Like as not, they’ll be able to figure out what it is, and behave accordingly. It’ll all be weapon and cartridge agnostic; like as not you’ll have a situation where you won’t even pick up your weapon until you’re in theater; the important bit will be that kit of electronics and optics built into your other gear.

            At some point in the near future, they’re going to have an IT guy down in the rifle squads. Won’t be any other choice; alternatively, you could well see a “crew chief/pilot” paradigm coming into play, wherein you’ll have to have a maintenance guy dedicated to each squad that does nothing but maintain the gear and prep it for action. Even a crew of them.

            End state, no matter what? The weapons won’t be that big of a deal; it’ll all be imbedded in the sights and other support electronics.

          • Kirk, I agree with everything you’re saying about the areas where real advances are happening these days.

            I think the problem is that you have to be able to recognize when you’re in a steady-state set of affairs with regards to technological advancement, and a period of revolutionary change.

            Sometimes. For one thing, the new-product cost and reliability / unknowns factors are constants regardless of which period you’re in. Second, the natural environment imposes a lot of constants too. Third, with few exceptions, innovation brings increasing modularity. Finally, it often brings efficiency / miniaturization as well. Oh, and the fact that firearms (and most mechanical – rather than electronic – systems) have been in an evolutionary state throughout the careers of practically everyone currently employed makes failures of recognition far less excusable.

      • The ammo weight is the point, though… You don’t get the effect you need without the volume of fire and the speed of the delivery you get with a belt-fed.

        Put a BREN up against the average belt-fed, in a fixed position firing at an oncoming assault. How many BREN guns do you need to stop that assault vice how many belt-feds?

        It’s all about the literal weight of fire you can deliver. The fact that you’re delivering it more slowly with a magazine-fed weapon isn’t helping you defend that position. At. All. If anything, thinking about it in terms of “Well, the ammo for those belt-feds weighs so much more…” is fallacious. How much does defeat weigh?

    • 1977. org was first one that had M72 as a weapon. 2nd and 3rd rifle section in each platoon had 9 men with 2 x M72 – 1st section had 2 x M53 (LMG role) and 4th was MG section with 3 x tripod mounted M53s). Ammo load for M72 was 465 rounds, 1 x 75 rounds drum, 3 x 30 rounds mags and 300 rounds on stripper clips.

      1981. org ditched M53s as LMGs, and each of 3 rifle sections (4th section was AT section with 4 x AT weapons) had 2 x M72, with 450 rounds per gun – 5 x 30 rounds mags + 300 rounds on stripper clips.

      1985 org reduced it to 1 x M72 (450 rounds), due the introduction of M76 sniper rifle to each of 3 rifle section (4th section was MG with 3 x tripod mounted MG)

      1990 org once again increased to 2 x M72 (450 rounds), by changing one rifleman to a SAW gunner.

      As soon as a war hit in 1991. M72s started getting replaced by M84s (PKM).
      This was made official with
      1993. org that had rfile section of 8 men, 1 x M84 (450 rounds, 2 x 100 rounds and 1 x 250 rounds ammo box, later upgraded to 550 rounds in 1998. org – 3 x 100 and 1 x 250 rounds ammo box), 1 x M72 (450 rounds), 1 x M76 (100 rounds), 5 x M70 (150 rounds).

  3. Opionated, but incisive and well-put. The logic of a good many weapon user reports is on a par with that of the graybeard biker, “I KNOW drugs can’t kill people. I tried everything and I’m still alive!”

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