Improvised Firearms




Amateur gunsmithing can be very rewarding, and can be a fun way to test your making skills.

ALWAYS be safe. Follow proper gun safety (Always keep it pointed down range). Be careful when testing. Do so from a distance.

Take inspiration for homemade guns from here:

Making your own guns also be very dangerous, as the people in the comments will likely tell you. Never fire a gun if you are uncertain of its safety. With that in mind, we can begin.

Step 1: Check the Laws

CHECK LOCAL LAWS! It is very important to know the laws in your state before attempting to make a firearm, as you could get in serious trouble. Always make sure your projects conform to law.

The BATF in the US regulates gunmaking, so you have to make sure you are not building a machine gun, short-barreled rifle, "sawed off 'shotgun'", or what they call an "any other weapon". Research these if you are making an unconventional firearm or anything with a barrel length of under 18" and overall length under 26".

The BATF website is here:

As far as state law, I live in Tennessee so no worries.

Step 2: Project 1: Simple Hardware Shotgun

12 gauge is the most commonly used shotgun shell around here, and building a 12 gauge shotgun is one of the best ways to begin gunsmithing. Imagine what the people at the duck club will think when you pull this out.

Here are the parts you'll need:

1. 3/4" galvanized or black steel pipe, schedule 40. At least 18" long unless you have a gunsmithing license.

2. 1" end cap

3. 1" steel nipple, 6" long. Try to find one with no weld seam on the inside.

4. 2x6 if you plan to make a stock yourself. I had one lying around. I won't go into how to make one, but this might be useful:

5. Nail

6. Strap wrench (for a barrel handle, optional)

7. 3/4 inch pipe brackets/clips

When you've gathered the parts, check out my instructable here:

If you don't feel like reading the whole thing, here's an overview.

The 3/4 inch barrel holds the shell, and when you pull it back into the 1 inch nipple it hits the nail in the back, firing the round.

Step 3: .45/.410 Pistol

There are many different ways to build a pistol, but a .410 or .45 is a good place to start.

I've included pictures of confiscated improvised pistols from other countries as inspiration.

Basically, what you will need is the following:

-3/8 inch pipe

-a handle

-a method of keeping the round in place

-a method of ejecting a spent cartridge

-a method of striking the primer

Beyond that, let your imagination go wild.

Step 4: Finish a Kit or Project Gun

Another way to continue your gunsmithing is to find a muzzleloader kit or buy a partially finished project from someone else.

I found a muzzleloader stock and barrel for only $30 at an estate sale, and the only part I had to make was the firing mechanism. I achieved this by spring loading a brass hammer attached to a dowel. The trigger seats into a hole in the dowel, and when it is pulled it releases the hammer to strike the cap.

Step 5: Testing

After you have built your masterpiece and have made sure it is legal, you can move on to testing. I tested my shotgun by using a really long string, and recommend you do the same. Always ensure that nobody is down range or close to your gun, as you are making sure it does not explode.

Finally, prepare yourself for the surge of happiness that accompanies the successful bang!


And happy hunting/overthrowing ISIS.



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    8 Discussions

    Possum Living

    1 year ago on Step 3

    For the .45/.410 pistol, either figure out a way to rifle it or better yet, use a section of actual rifled barrel. In the USA, smoothbore pistol = felony.

    Another option would be to build it as a muzzleloader, since firearms laws don't apply to most muzzleloaders.


    2 years ago

    Being an Engineer who know such things, I think it needs mentioning that 1010 grade pipe steel, intended for 1000PSI Max is no substitute for 4140-4150 gun steels intended for 5000+ PSI chamber pressures! Even more so because standard SCH40 pipes are thinner wall than modern shotgun barrel main pressure sections, and the seam welding process used to make most pipe components does not handle sudden pressure spikes well long term.

    That's not to say pipe shotguns will blow up on the first shot, clearly they don't, but it is to say wear heavy eye-protection when using and replace the pressure section every 100 rounds or so.

    6 replies

    Reply 2 years ago

    pretty sure that early day gun makers did not have access to 4140-4150 gun steel, as a matter of fact a great many of the early guns were made by the local black smith.


    Reply 2 years ago

    Quite agree. What do you think of carbon steel hydraulic tubing? For example I've seen some 3/4" ID pressure rated at 495 bar or over 7000 psi.


    Reply 2 years ago

    Wrap it in duct tape and use the tensile strength to reinforce it right?


    Reply 2 years ago

    Duct tape will not add any strength, as its waaaayyy more flexible than steel. What it can do is greatly minimize shrapnel if the main pressure section fails, if you wrap a 1/8" layer of tape around it.

    Wrapping it in fiberglass however, would help, but only so much.