From Bolt Action Lee to LMG: The Charlton Automatic Rifle

The Charlton automatic rifle is one of very, very few examples of a conversion from bolt action to self-loading rifle actually working reasonably well. Typically this sort of project founders in expense and unreliability. Charlton, however, was able to take his vision for providing the New Zealand Home Guard with a new weapon made form obsolete surplus and bring it fully to fruition, with 1500 guns made. They were never fired in anger, but allowed New Zealand to put all of its Bren guns into the field while retaining Charlton as emergency weapons in case of Japanese invasion. Sadly, virtually all were destroyed in a warehouse fire after the war, leaving them extremely rare today.

Many thanks to the Royal Armouries for allowing me to film and disassemble thevery scarce automatic rifle! The NFC collection there – perhaps the best military small arms collection in Western Europe – is available by appointment to researchers, and you can browse the various Armouries collections online.

For the whole detailed story on Charlton manufacture, and to download a copy of the manual, check out my full article.


  1. “Take our island, will you?! Insult us as evil colonialists, will you?! Bugger off, you ***s!” [30 round magazine dump] “Keep the change, you filthy animals.”
    I couldn’t help but think of someone doing that, since there’s a Thompson style hand grip as opposed to a flat hand-guard. Yes, this was a joke post.

  2. Thanks for this great piece about a gun which has always interested me. I had never read that the Charltons were based on Lee Metfords and Long Lee Enfields, so that was great information.

    Sadly, no inventors in New Zealand will ever produce another semi-automatic rifle, as that country has now followed Britain in decreeing that no modern rifles may be owned by law abiding Kiwis. As ever, criminals are free to do whatever they like.

    • That’s kind of the problem: crooks don’t care! The standard procedure if a British building gets held up by a madman wielding a world war bolt action seems to be “scream for Police and wait for them to save the day while madman bayonets everyone dead or just shoots them.” Just kidding!

  3. I guess that a British style Lee, with Speed’s screw threads attachment for the bolt head,

    Is actually a good candidate for this type of conversion

    The bolt operation has a positive rotation stop for both locking and unlocking, with that big right hand locking and guide lug hitting the sides of the ejection port. There’s far more surface there than there is with the little bits of locking lugs contacting the extreme front ends of the bolt raceways on a mauser or most “Mannlicher” actions (OK, the post 1903 mannlichers did have a good big guide rib).

    The Lees also have a very strong bolt stop system,

    And they’re already set up to take detachable magazines. Even though there would be some work to do to get the BrEn mag to fit, and feed and to get stop surfaces to prevent over insertion of the magazine into the appropriate places.

  4. I swear this project had to be up there with the G11 for shear boondogglery. In what universe was this contraption going to be an effective combat weapon? Talk about missing the forest for the trees (can’t blame the designers, they were just doing what they were paid to do, after all; the blame is with the idiot military pursuing this ‘retrofit’ concept in defiance of all reason)

    • Well, easy for you to say that. You’re not the one short on proper materials for proper machine guns. The alternative for this was waiting several weeks for Australia to ship some crates of guns and magazines to New Zealand, assuming the boats didn’t get attacked by the Imperial Japanese Navy first! Yes, this is just an assumption…

      • New Zealand was at the very, very, very end of the supply chain as far as the Allies were concerned. As was noted, New Zealand’s army was going to take every real machine gun to go fight wherever the Empire told them (meaning London/Washington). The government’s obligation to defend the people at home didn’t matter to those guys. So you’re stuck with the Home Guard, and the ancient rifles it already had. Think any taxpayer in Pittsburgh or Manchester was going to pony up a penny for New Zealand’s self-defense, much less find room in their factories to make real machine guns to ship there?

        And ultimately, only test and field results matter, and you weren’t there for the tests. I’m betting anything based on a Lee is going to be more reliable than certain Japanese machine guns that oiled every cartridge before insertion. Talk about contraptions.

        • The Type 92 heavy machine gun was okay so long as the crew cleaned it and oiled it right (as opposed to neglecting the thing until it jammed shut or broke, as some American rookies would do to the Browning M1919). And it more than compensated for its low strip capacity by having long range and decent sustained fire accuracy, especially with optical sights. Oh, and the oil having to be added was symptomatic of varying cartridge case quality not agreeing with harsh extraction. The French had similar problems with their 1914 heavy machine gun… did I mess up?

    • Barnbwt:

      Did you watch the video? The Charlton gun was a cheap conversion designed to give reservists some sort of automatic weapon. The alternative was no automatic weapon. How is this a boondoggle?

      I has not realised they were recycled from Lee Metfords and Long Lees. The Illustrated Encyclopedia of Firearms by Ian Hogg says they were made from a “standard Lee Enfield”, which implies an SMLE. It also says that only 500 Charltons were ever made, by Electrolux in Australia, so Ian giving me interesting new information.

      Sadly, although most of the 1500 Charltons were destroyed by fire, the reality is that the New Zealand government would certainly have scrapped them anyway sooner or later. The British addiction to gun control and gun confiscation is just as strong in the Commonwealth, as gun owners (or former gun owners) in Canada, Australia and New Zealand can confirm. We are lucky that a few Charltons survive in museums.

      • “Sadly, although most of the 1500 Charltons were destroyed by fire, the reality is that the New Zealand government would certainly have scrapped them anyway sooner or later.”

        Probably almost immediately, as in, within a couple weeks of actually being fielded. My point about it being a boondoggle, is that the time, effort, and materials that went into this project could have been better spent to make truly useful firearms. Obviously they didn’t know this at the time, but in retrospect these conversions actually weren’t critical to preserving the territory, since they were lost in fire yet didn’t result in catastrophe. It certainly appears the military were panicked and chased a ‘solution’ that was foolish, but seemed cheap & easy at the time –in practice it was neither, since even a ‘quick’ conversion like the Charlton had its costs and yet didn’t produce a useful weapon.

        How many times have nations attempted to retrofit legacy weapons to modern tech for cost or schedule reasons? How many times has it EVER been worth the effort? The F18C is probably the most successful example…and even it wholly replaced an awful large portion of the original, just to get an extra decade maybe longer out of the chassis.

        • Barnbwt:

          I think the point about the Charlton is that it was indeed a useful weapon. By converting an obsolete bolt action rifle, the New Zealand Home Guard got a reasonable automatic weapon, when the alternative would have been no automatic weapon.

          New Zealand in 1941 was not an industrial nation. It did not have the ability to design and make a viable machine gun from scratch. The Charlton was a very efficient conversion which gave the Home Guard some sort of automatic firepower when they actually needed it. Luckily the Japanese never invaded, but things could have gone differently.

          There are umpteen scams and boondoggles when it comes to military procurement, I just don’t think the Charlton fits into that category.

          • Good points, sir. I tried to say it earlier: you can’t make “proper weapons” if you lack the facilities, the technical personnel, the tools, and the materials for such! Could a random American machinist working from a garage create 10 acceptable M2HB guns within a week, having been given one set of drawings but no steel stock, no additional tooling, and no testing ammunition? I think not!

        • “(…) F18C is probably the most successful example…and even it wholly replaced an awful large portion of the original, just to get an extra decade maybe longer out of the chassis.(…)”
          Keep in mind Charlton was using existing barrels which are crucial elements requiring much effort to make it work as intended, as inner dimensions greatly influence spread and yet it is element which is most exposed to heat from firing (especially in full-auto weapons). So question is: could New Zealand, back then, produced better machine gun barrels than those actually used?

        • They were destroyed in a fire AFTER the war. After they were no longer needed. Which is why it wasn’t a catastrophic loss — they had plenty of real Bren guns, if need be, left over from the war, by that point.

          In the meantime, the Home Guard reservists had SOMETHING, which they almost certainly would not have had, during the days when a Japanese invasion was a very real possibility.

          And it enabled them to reuse the most difficult parts to tool up and make from scratch – the barrels and bolts.

          Would it have sucked, compared to most LMGs? You betcha. But it would have sucked less than the alternative (i.e., NO LMGs).

  5. To put this in context, a Youtube video examining the truly ridiculous Huot machine gun converted from a truly useless Ross rifle in WW1 Canada noted that the price of a conversion was $50 Canadian, while the going rate for a Lewis Gun was a likely-extortionate $1000.

  6. Charlton deserves credit for more than just the conversion; he avoided missteps made by the designers of the “real” machine guns. A separate guide rod and recoil spring away from the piston, unlikely to be affected by heat, unlike Degtyarev’s first design. A buffer at the end of the piston (that’s in the odd, fat cylinder mounted at the back end of the guide rod), so the gun doesn’t beat the shooter up too badly, unlike the Johnson. Stuck with a fixed barrel like the Chatellerault? Add Hotchkiss cooling fins! Charlton seems to have known not just engineering but a wide vista of firearms facts.

    Speaking of pounds and pence, what did the conversions cost? (Though in desperate times perhaps cost was no object — and there was not much compensation paid to these people I’m sure.) And surprisingly the gun was durable, but was it at all accurate?

  7. My biggest engineering concern is honestly, was the Bren magazine spring strong enough to reliably lift cartridges fast enough for the ROF? It’s not a terribly strong spring, and in its designed application has the advantage of gravity assist, unlike here.

    • Rick:

      That is a valid concern, but would have been easily addressed by only loading, say, 20 rounds in the magazine. The Charlton gunner would thus have had the firepower of a BAR at a fraction of the price!

  8. At least the Kiwis had a working weapon, as opposed to the “hands up and beg for mercy” routine I was taught in Cleveland. Not kidding, local politicians told me, who would rather run and then find a way to get revenge, to cower and kowtow if confronted by agents of an occupying “New World Order” who would torture me just for being American. I will die as a free man rather than as a slave to tyranny.

  9. NZ had sufficient Inglis Brens delivered by early 1944 and the Charltons were withdrawn from Home Guard units and stored at the Palmerston North racecourse which was being used as a major storage depot. The depot caught fire on 31 December 1944 and 22 million Pounds worth of equipment was destroyed, including the Charltons. Only 10 Charltons exist today, 7 in museums and 3 in the hands of private collectors of which I am fortunate to be one. The trench magazine shown in the video is incorrect and has been added by the Royal Armouries. The Charltons were issued with the standard 10 round rifle magazines, as the 30 round magazines manufactured by an Australian contractor did not fit and had to be altered for later issue. These magazines were not modified Bren mags but were a purpose build magazine of similar design to the Bren. The only true Bren mag parts were the spring and base plate. The casing and follower were purpose-made parts specifically for the Charlton. My Charlton is fitted with one of these very rare (only 2 or3 left) 30 round mags. The scroll cam release plate that you struggled with in the video should have small stud fitted in the hole which makes the operation much easier!

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