Kongsberg M52: A Line-Throwing Rifle (or Harpoon Gun)

The Norwegian Kongsberg factory has a history of making firearms-based tools for maritime use, and one of the more recent is the M52 line-throwing gun, introduced in the 1950s and sold through the 1970s. It uses a repurposed Mauser action paired with a new smoothbore barrel and a 12mm blank cartridge to fire a rescue line. A couple of different projectile heads were made, including a floating wooden one, a smaller solid steel one, and rocket-assisted ones to increase the range from about 100 yards to nearly 300 yards. Two versions of the same basic gun were made, one for throwing line (for maritime rescue, firefighting, and construction) and one as a harpoon gun for hunting whales. This example is line thrower, and particularly cool because it includes the complete original case and accessories.


  1. Makes me wonder… What are they doing, these days, for line-throwing guns?

    It’d appear that the most-recently produced model was based on a .45-70 break-open single-shot action, but that’s gone the way of all things flesh and is no longer in production:


    At least, per several of their distributors. Something “new and improved” is supposed to be in the offing, but… Who knows?

    This is one of those areas that’s a lot harder than it looks on the outside. We did some early experimental testing of a line-throwing kit for the M16 back during the early ’90s, with the idea being that you’d be able to get a lot more distance out of a system like that than by throwing your grapnels (for tripwires) by hand. They worked, kinda, but… The entire idea sort of foundered on the idea that you’re normally doing grapnels for stealth breaches, and firing your rifle wasn’t a good idea to maintain stealth. Plus, the line wasn’t all that sturdy and the launched grapnel tended to get hung up in things… Wasn’t quite the wonder-tool everyone expected it to be, and like a lot of “good ideas”, the Good Idea Fairy™ giveth and then immediately taketh away…

    • I’d be curious to see what kind of harpoon system the Inuit who still have the special dispensation to hunt whales are using these days. I remember being told that a few communities in I think Alaska or Nunavut use rifles in 460 Weatherby to finish the ones they catch, but not what they’re getting them with in the first place

  2. Guns and Ammo had a feature on this, and another harpoon gun, back in the 70’s. They fired dowels with a nut on the end for weight.

  3. I’m aware of pneumatic and rocket powered modern line throwers.
    you may search for the “Ikaros” thrower, for example.

  4. Hello, where is the MG3 video? I was looking forward to the discussion in the comments here 🙂
    Same thing with the MP-41(r) video that was posted on Youtube a couple weeks ago but never appeared here.

  5. Pop a grenade towards the end of that rod; and you have an “xm125 airburst future tech device” simply, pop it in barrel as per; slot grenade into a “holder” slide over fly off lever holder; connect this to (Line) remove pin… Pull out at rear, of modified line drum “Range” I.e. has 150m of rope, so 25m for 125m for example… Rope that is marked for (pin removal) to detonation; so 6 secs’ish in regards flight.

    And it will air burst at 125m.

    Pop Viet Cong massed battalions charging with air burst grenades in 1963 like it was 2003 and never happened, missed a trick there if you ask me in the 60’s.

    Air burst grenades at say 85m away, would be better than trying to lob them at a rapidly moving towards you target.

    Cheap. And I think potentially very effective; airburst.

    • Ok; bulky etc… But hey, it delivers xm125 peformance “Which is good” one in war will not want ones precious explosives being lessened in effect by mud, some rocks, a few trees… A horse etc.

      Think of the efficency gain.

      • Mark rope range with those tags you get on bread “for sell by dates” E.g. a blue 125m marked tab then say 23ft etc back red tab, thats what pulls the fly off lever cover off for 125m hit; so grenade arms, 6 sec of flight so approx 125m “Do the math prior in actual use” BOOM!!! Say 5ft above head height. Oh that would take loads of the hordes out, far more efficient than 40mm grenades for example.

    • “(…)150m of rope(…)”
      Please compute weight of that required for your purpose, then compare it with weight of grenades (how much of grenade+ropes vs bare grenades you might pack in same weight limit) and how feasible would be loading such contraption in real combat.

      “(…)1963 like it was 2003(…)”
      Be warned that XM25 does impinge at laser rangefinder for determining distance, which is more precise than using your eye and whilst laser was patented in 1959 it was seen a solution looking for a problem and first large-scale application for lasers was the laser scanner for automated checkout in supermarkets, which was developed in the mid-1970s and became common a few years later.
      which raise question if it is possible to mass produce portable laser rangefinder suitable for field usage by 1963 technology.

      • I think we can do it! I think we should with Ak and Ar platforms; just in case, won’t sell most folk don’t have… Grenades. Hey! “What?” you may say in Czech or whatever. I via x16 mag binos saw a ufo last Friday. Cheap binos with a shit focus. But I can tell you this; it was not a plane or chopper.

        So it was a drone. A chopper sized drone that looked “Via a glimpse like a chinky jet drone” but it hovered, then shot into space.

        Mars attacks, alien mofos he he.

        Do everyone in the world a favour; work out what you just said, line lengths to detonations.

          • “Nobody has a xm25 you need to do the math, for a cheap version.(…)”
            But whatever you elect to do that without machine or using device, you need to first know distance to target. Therefore describe such device which could be mass issued in 1963 or provide evidence that using eye is sufficiently precise for proposed situation.

          • You are right there; incriment marking in scopes, laser range finders… Paralex, focus things, not fired a weapon me for ages; for someone who goes on about guns so much. I don’t want to own one. I would like a flintlock/gatling gun etc in Montana.

            Phew “Just had some hot chilli sauce; burned my tongue.” what are you asking me?

            Happy Easter by the way, Jesus’s 2nd birthday when he arose from a chocolate egg I think.

            I like Jesus.

            What are we talking about Mazda engines?

          • The Ufo looked like a But the back > was higher. Mazda engines; some good ideas, for the combustion engines I think. Burned my tongue that chilli sauce…

          • at the back, very similar to a large seagull… Really, at range… Pissed. Through x16 mag binos for 2 secs.

  6. Was probably a large seagull; I do drink alot…

    “Trying to put the men in black off my tail, about ufo’s”

  7. Those pictured harpoons are actually pretty neat. I’ve got one as a curio. The small hole through the nose holds a match stick that holds back a small brass weight in the tip. On firing inertia breaks the stick and the weight hits a percussion cap and ignites about an inch long piece of fuse that you fit into a tube, that leads into the black powder filled main body. Simple but clever.

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