DIY Sten Gun

Here’s another design sent in, this time for a simplified copy of the classic Sten gun. As pictured, It’s possible to construct a clone of the original bolt using only a drill and an angle grinder.


homemadestengunbolt nonfiringdummy


The example shown was of course constructed as a non-firing dummy replica for obvious legal reasons. All information contained is strictly for academic / technical study and entertainment purposes only.


PDF:  The DIY STEN Gun – Practical Scrap Metal Small Arms Vol.3

DIYstenguncover small


  • Bubba

    Awesome. I’m totally saving this one!

  • guest


  • Jordan Varmette

    Wonder if you could make a pistol with a Sig arm brace on it?

  • wetcorps

    Nathan should build one as a “dealer sample” and review it 🙂

    • noob

      The really crucial thing I’d want to know is what is the cheapest/most commonly available steel that is available in most locations that you can use to make the barrel and chamber. that piece of machining and metallurgy is the difference between a working weapon and losing your fingers/face.

      • Bubba

        It’s not as demanding as most people think. You can make barrels of mild steel, but the chamber area needs to be a bit thicker, and the rifling will wear out pretty rapidly. But it will work.

        If you’re really lacking tools an improvised barrel can be made out of sturdy hydraulic tube with an inside diameter of between 8.8mm and 9mm. If you leave it smooth bore it won’t be accurate, with a maximum effective range of about 20yards.

  • Mystick

    I won’t say it again. I know. You’re welcome.

    • Larma

      Something about an ghost of Arab decent not wanting to go back to from where it came from. Na, let’s ban hand files.

      • Mystick


  • Xaun Loc

    This press releases for DIY no tools needed firearms are just a scam to sell the overpriced instructions to people who don’t realize that it really ain’t that simple.

    • Zips

      Australian police disagree….

  • Xaun Loc

    “it’s possible to construct a clone of the original bolt using only a drill and an angle grinder” Sure it is — provided your drill and angle grinder can recess the face of the bolt to exactly fit the base of the round AND leave a properly centered, properly shaped fixed firing pin in the middle of that recess. The sten doesn’t require a LOT of fancy machining (not compared to something like an AR) but there are several parts that are more critical than the advertising for these “instruction manuals” would lead gullible people to believe.

    • iksnilol

      It is easier to just make a laminated bolt. You take pieces of sheet metal and layer it, cutting out pieces with an angle grinder or file to make the rails and whatnot. Really hard to explain so just check it out here:

    • Tok

      Which parts do you think are so critical that you NEED a lathe or mill? The example shown is basically a Luty SMG in a Sten’s body. What you’ve described doing is child’s play in the realm of blowbacks. There are plenty of threads on forums showing people making even more complex closed bolts using the exact same low tech methods.

      • Xaun Loc

        Even a safe barrel and chamber are far beyond the abilities of 99% of the people these instruction books are meant to be sold to. Yes, you can cobble a working sten together out of an older parts kit using simple tools, but building one from scratch is NOT a job for just “a drill and an angle grinder”
        Most of the boobs buying these books would have trouble building the pipe, wood stock, rubber band, and nail shotgun that the OSS distributed plans for in WWII.

        • Ex Armorer

          You’re no one to speak.

          You can’t grasp how simple it is to drill a hole in the bolt face to accept a fixed firing pin, and yet you’re dead certain that no one can manage to cobble a simple open bolt SMG together.

    • Zips

      Here’s a video of a more complex weapon design that was build without a lathe or mill… .. Even the firing pin channel was done by eye using a hacksaw…

    • BryanS

      I wouldnt doubt that you could machine that recess with a clever bit of grinding on a drill bit to make it less pointed.

      The guys in the Philippines and Pakistan, who make good functional 1911 copies with hand tools will probably disagree with your sentiment. Just because you currently dont have the skills to do this does not mean the rest of your countrymen do not either.

    • HSR47

      “recess the face of the bolt to exactly fit the base of the round AND leave a properly centered, properly shaped fixed firing pin in the middle of that recess.”

      Drill out the area, then weld up a spot in the middle. It doesn’t have to be absolutely perfect; there is such a thing as “close enough.”

  • Hat
  • Tenacious221

    They were DESIGNED to he simple to manufacture after all…

    • Xaun Loc

      They were designed to be simple to manufacture using standard firearms factory equipment.
      Actually, functional firearms can be made without any power tools — after all, firearms were in regular use BEFORE power tools were invented. But that doesn’t mean that a safe, fully functional, firearm using modern ammunition can be tossed together out of random scrap using your trusty pocket knife and a roll of duct tape, by Larry, Daryl, and his other brother Daryl.
      Yes, someone with the right skills, patience, and the right hand tools could create a reasonable copy of many of the simpler modern firearms — but such people are not the audience that are buying these books.

      • PPK

        … but these PDFs are entirely free.

        An angle grinder, welder, drill, hacksaw and files are hardly akin to duct tape… You don’t know of Luty, do you son?

      • Mr Evilwrench

        We’re not building something that’s intended to be “safe” or “long lived”; we’re making something functional enough to use against an enemy that has a manufactured weapon, then take his. Trade a garage sten for a DHS UMP .40 or M4, then go to town. But that garage sten will get you to the UMP .40 a lot faster than a pointed stick.

      • screwtape2713 .

        You don’t know much about your firearms history, do you?

        The SMGs like the Sten and the Leningrad version of the PPsH were designed to be simple enough to manufacture that they could be made by companies (in the UK) or just people (in places like Leningrad) with standard machining equipment but without “standard firearms factory equipment” (whatever the heck that is) and little to no experience in the manufacture of firearms themselves.

        BTW, what exactly IS this “standard firearms factory equipment” you refer to anyway? About the only thing I can think of off the top of my head would be a specialized boring machine for cutting the internal rifling in the barrels. Anything else in a WW2-era factory making Sten guns or even just some of the parts for them was pretty much standard metal fabricating equipment.

        Do you mean CNC machines and so forth? Because you certainly do need that type of equipment nowadays to produce firearms on a commercial scale at a viable price point. But you certainly DON’T need it just to build a single gun over time for personal use or even a handful for yourself and friends.

        • Xaun Loc

          Well, screwy, apparently I know more about firearms and firearms history than you will ever learn (if you do ever learn anything). The point I made was that the Sten was never designed to be thrown together at home by bubba with an electric drill and a grinder — as even you realize all the real firearms we have been discussing have rifled barrels and the majority of them have chambers bored accurately enough for the round to headspace on the case mouth. These so-called instruction manuals are mostly sold to drooling idiots at gun shows and prepper events — the manuals claim that the complete firearm can be built by anyone with the kind of simple tools found in a typical workshop or garage. The say “drill” but the reality for any chance of real success in copying even a simple modern firearm (such as the Sten) is a drill press. For most of the firearms that are typically described, a lathe and/or milling machine may not be absolutely essential, but make the difference between a rational project and a pile of junk that gets tossed after sitting on the workbench for a year or two. Likewise welding equipment may not be absolutely essential, but trying to align and attach a magazine well to the receiver tube of a Sten is no picnic with a vice and some epoxy.
          There are lots of one-time-use firearms that really can be built without major metalworking tools, but those aren’t as sexy as a Genuine Imitation Sten SubMACHINEGUN.
          Building a semiauto or full auto firearm that will safely feed and fire modern ammunition requires precision that might be achieved by skilled artisans using “simple” tools and a lifetime of experience — but not by the usual market for these manuals working on their first project.
          The charlatans pushing these Build Yourself A ______ Machine Gun manuals originally fell into two categories: The crooks conning people into just buying the manuals and the bigger crooks conning people into buying the manuals so that they will come back to buy the parts kit before still failing to build a working firearm. Most of that second category have quit as the supply of cheap parts kits dried up, but every gun show will have at least a few vendors trying to sell Xeroxed or QuikPrinted copies of these silly manuals.

          • screwtape2713 .

            I just logged onto this website again and found the continuation of the discussion.

            Ignoring your completely unnecessary insults (“screwy”??), I think the difference between us might possibly be the type of environment in which we live. I’m not sure where you live or what type of people you commonly meet, but I grew up and still live in an area of my country that relies heavily upon agriculture for its economy.

            That’s a fancy way of saying that I grew up and live around a whole bunch of farmers and farmkids.

            Some of them have taken formal professional training and certification as welders, millwrights or heavy mechanics, but many just learned from older relatives and by doing. And again, some have fairly complete metal shops on their farms or in their garages in town – often assembled over a period of many years – but many of them actually have access to hand and power tools at about the minimum level of that called for in these plans.

            Based on your comments, I think you would be absolutely stunned to see the sort of stuff those guys can make when they put their minds to it – using just junkyard scrap, fairly simple tools and their imaginations. I can think of at least a couple dozen guys just off the top of my head who could knock one of those toys out with no problem at all, if they wanted to.

            Of course, my personal view on the practicality of those DIY Sten Gun plans might also be partly affected by the fact that I KNOW it’s doable, because I have personally SEEN it done.

            In fact, on one of those farms I just mentioned, which is located located somewhere within my home province, on a lovely fall afternoon that occurred sometime between August and October on a year sometime between 1990 and now (and for obvious reasons, I am never ever going to be more specific than that), I spent a few hours visiting one of these types. And in the course of that afternoon, it came about that I had the opportunity not only to view and handle such a DIY SMG but to testfire it on the back 40. And you know what? It worked just fine…

            Oh yes, and that particular guy was one of the ones who was NOT a professionally trained millwright and did NOT have access to a complete metal shop.

            Of course, the last part of your comment, you seem to “assume” for some peculiar reason that these manuals are DESIGNED for an urban 8th-grader who has never held a simple hammer before in his life and is going to pick the DIY Sten Gun as his very first shop project… Personally, I’m not sure where you came up with that assumption, because I didn’t see anything in the plans myself that specified “designed to be usable by a fumble-fingered idiot with no experience whatsoever in ever building anything”…

          • Tom Currie

            You really cannot comprehend the difference between what can be done by a person with training (formal or informal) and a fairly complete machine shop (typical of many rural communities) versus what the untrained urban wannabe can do with regular hand tools.

          • Dirty Old Armorer

            Xuan is an idiot.

            His firearms “expertise” appears to be based on a lot of time behind a video game controller.

            The Sten was in fact designed to be manufactured by NON-FIREARMS companies which had basic metal-working equipment available.

            Hundreds of Stens were manufactured in Norway, Denmark and the Netherlands by bicycle mechanics, janitors and other non-professional non-gunsmiths.

            Judging from Xuan’s shrillness about mechanical incompetence, I suspect he calls the electrician when a light bulb needs replacing.