Airtronic’s Modernized 40mm China Lake Grenade Launcher

In 2004, a trio of small arms enthusiasts began an effort to reproduce the Vietnam-era China Lake 40mm pump action grenade launcher. They displayed their first prototype at SHOT Show, and (not surprisingly) got quite a lot of interest in it. Their production plans quickly went form 1 to 3 to 10 and then to 50 units…far too many to built one by one by hand as the prototype had been. Looking for a source for barrels, they wound up in contact with the Airtronic corporation. Airtronic was then primary contractors making M203 grenade launchers for the US military. They could easily produce a few dozen barrels, but they expressed an interest in mass producing the gun.

At about the same time (in the aftermath of the Battle of Fallujah), the USMC began a process to find a multiple-shot 40mm launcher. Specific interest was expressed by the Marines in the China Lake, and Airtronic began to change the original design to better fit modern military needs. Some of these changes were simple and suitable, like replacing the old M79 iron sights with Picatinny rail for modern optics, and replacing the stock with an AR-pattern pistol grip and buttstock. The really problematic change was an attempt to lengthen the receiver and allow the gun to use the high pressure grenades of the Mk19 automatic grenade launcher. This would not have proven feasible, but the project never got as far as a completed, firing prototype.

Instead, questions of ownership, licensing, and money broke out. The original three partners and Airtronic wound up in a lengthy and destructive lawsuit, which would lead to Airtronic declaring bankruptcy and no complete guns, either original pattens or modernized, being completed. This prototype is the only surviving example. The USMC would end up trialling the South African Milkor MGL-140, modifying it a bit, and ultimately adopting it as the M32A1.

Many thanks to Dutch Hillenburg for making this video possible!


    • I would say change was an attempt to lengthen the receiver and allow the gun to use the high pressure grenades of the Mk19 automatic grenade launcher sounds like serious change in requirements when work was already in progress, which is alarming.

        • From my distant memory, there are often “fiddlers” on scene. They do not understand a damn of your intent, but they want to have “fingers in the pie”. They are the utmost in annoyance, especially if management lends them ear.

      • I wonder if the 40mm high velocity requirement was intended to compete with FN’s HV-40? with the high pressures and velocities would not have been something I’d care to fire twice. the HV-40 had a lot of recoil dampening that this wouldn’t, and I’ve read that was pretty punishing.

        • or perhaps the knights armaments EX-41 from 1995? that used “medium pressure” grenades, about halfway between the high-lo pressure and the Mk19 rounds.

        • With the 1″ buffer tube, quite a lot of recoil dampening could have been added to the stock. Quite the object lesson on how not to resurrect history.

  1. So instead of making a ton of money they just ruined each other. Brilliant.

    Scrooge McDuck had this motto… “It’s better to sit together on a pile of money than alone on a pile of rubble.”

    • “(…)instead of making a ton of money they just ruined each other. Brilliant.”
      So they were ardent adherents of In case of doubt launch lawsuit rule?

      • Or, as it appears, a lack of good communication and team effort caused everyone to start pointing fingers. And then the Marines wondered how the heck anyone got anywhere with these idiots.

  2. Knock one up with a Breda type… Harmonica mag, is it… Four round clip; lose the tube mag thus. Pump to play “the harmonica”

  3. Do you know Nitinol right “yes I am on about that again” do you think… Well do you know when it changes shape… It creates pressure if resisted as it (Simply must change atomically etc) could… That pressure be… Used “theoretically” to add, er… Resistance thus strength to say a chamber, thinking shear thickening fluid kind off I.e. Not hard then hard, so no pressure then pressure. I get the 40mm rounds have there own chamber in the round, but it could maybe be used to add strength to both. Perhaps?

    Tell you were I started from 5 mins ago; a barrel over this barrel with an explosive charge acting on it “in it” point was; the pressure created counter acts the pressure acting outward from the actual barrel… To push it back in. Strength thus. In away.

      • I won’t go on “and on” but, imagine a 40mm round it has a wee “chamber” in it, which means your actual chamber can be thinner (as is my understanding) so, what I mean is… Or started with, is basically that but instead of mass resisting barrel expansion its pressure… Now perhaps the outer sleeve would need to blow off as what would contain it “Russian doll” type thing. However maybe there is an equilibrium to be found. I.e. it just about works, but is lighter than a normal chamber.

        Thinking for the Mk19 grenades.

        If so, and its fair cheap… Easy enough. Why not.

        • Could call it; Fiddler on the Roof, that m321a1 gun is very respectable, but its a fair size… This pump gun is a fair size; Breda clips could, give it a diet. 4 quick loads.

          • Big revolver… 40mm Grenade launcher thing, with the AR “Car 15” type, extending stock; looks like one of those giant revolving shotgun Sud Afrika knocked up. You know what I mean… “Aye that” so thats what I meant the m20321a1aksu bomb chucker.

        • Bet you could do the “russian doll” thing, by putting multiple case outers “telescopic” inside the other with vent holes _- staggered up, up, and up so it goes bang but “bleeds” and re-seals case/gas expands, forward to vents… Actually I may need a pen, getting more complex he he.

          • Sort of api… In regards the chamber. I.e. The round sits within it, then expands forwards as oppose being pushed forwards. Or maybe not. No it is’ish. Anyway all good, if confused. Fiddle away I say.

          • Not api in regards the recoil no. Actually if you were making a gun and I suddenly floated down via a brolly like Mary poppins and started balet dancing around your gun hitting it stardust “from my magic wand” I could certainly see we you may throw a cup of tea at me. Still… Anyway, Merry Christmas he he.

      • Duck noise… QUACK! “You know Ducks” Quack, quacks. I met one that used to knock on my door with her beak… Bill… Nose thing. A girl Duck, her husband a boy Mallard looked a bit like perhaps it wasn’t such a great idea by his Mrs; but it was really, as I gave them both some bread.

Leave a Reply

Your email address will not be published.