The Vaunted PKM Machine Gun – A Closer Look, from Forgotten Weapons

    The Russian PKM: Arguably the best general purpose machine gun in the world, it combines a robust reliability with best-in-class light weight. Ian McCollum of Forgotten Weapons recently released two video overviews of the weapon, giving us a good enough excuse as any to spend some time with the Soviet showstopper:

    As supplementary material, I also recommend checking out Reddit user Oelund’s review of the PKM.

    A careful look at the PKM’s design reveals the secrets of its lightweight construction. Unlike most machine guns, it lacks a rear backplate, substituting it for a permanently attached trunnion assembly, like an AK rifle. This eliminates the need for robust dovetails, threads, or other assemblies that need to be reinforced enough to both take the substantial beating from the bolt group and still come off and on consistently. Also, the feed pawl mechanism is radically different than that of guns based on the MG-42 system, using a small, simple pivoting arm pushed out to the right side by the bolt carrier, rather than a much larger (and therefore much heavier) articulated feed cam, lever, and pawl assembly like the M60, for instance. As a study, try comparing the design of the PK’s feed pawl lever and the feed pawl assembly of the ill-fated X11E4 machine gun covered earlier this month. Finally, the PKM lacks a large handguard or barrel shroud, further saving weight on a gun that probably does not need them anyway.

    These features together pay a significant dividend: The PKM is comparable in weight to an M249, despite being chambered for the much larger and more powerful 7.62x54mmR round! However, I am not sure I would describe the PKM as the king of machine guns, or at least not make it the sole sovereign. The Belgian MAG machine gun, used by US forces as the M240, though significantly heavier, also possesses exemplary characteristics that make it too arguably the best machine gun ever made… Depending on what it is you want out of a machine gun.

    Of course, it’s difficult for most of us to truly be able to compare the PKM and M240 to determine which is the best… Which is why I asked Ron Cheney, co-owner of Battlefield Vegas and one of the very few people really qualified to compare the two, what he thought:

    Our 240’s have held up better over the PKM’s. We’ve lost two front trunions and three rear trunions [on PKMs] but have never experienced any cracking/breaking of 240 receivers.

    Also, we’ve only lost one op rod on the 240 as compared to at least four on the PKM.

    That being said… If I was a door-kicker and humped them around, I’d take the PKM.

    So maybe we should say the M240 is the superior machine gun… Until you need to pull it off the mount and carry it!

    Nathaniel F

    Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. He can be reached via email at [email protected]