How to Make a Pneumatic Air Gun




About: Here i feature various projects from my YouTube channel and website. i do lots of small office supply weapons and some small vehicles too and some stuff that might be used for science experiments. i try to d...

In this tutorial i will be showing how to make a pneumatic air gun. Its an interesting build that utilized air pressure that is hand compressed in a piston and released through a valve to fire a projectile. The materials were bought at hardware stores (will be listed on materials page) but as a few are expensive so i recently came with a version made with more obtainable materials such as syringes new version . But, you can see a short preview of the syringe version working in the video of this gun attached above.

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Step 1: Materials

For this build you will need some tube, a valve, and a piston. all of these i found at princess auto which is an auto and farm surplus store. I also bought an aluminum hollow tube for the barrel of the gun and a solid steel pipe that fits perfectly inside the aluminum tube to make an airtight seal.

Step 2: Making the Bullet

I first cut the aluminum barrel down to 55cm. After that i went ahead and cut the projectiles out of the steel pipe to an approximate length of 2 cm for each projectile

Step 3: Preparing the Valve

Next i cut out 2 pieces of the plastic tubing and pushed it into the back two holes in the valve.

Step 4: Attaching the Valve

Next i flipped the valve upside down and glued its flat side. Then i placed the piston on the glue and attached one rubber tube from the valve to the back of the piston so that when the piston is pulled in it will force the air into the valve.

Step 5: Preparing the Barrel

Next the aluminum tube was attached to another rubber hose by pushing the hose over the tube

Step 6: Attaching the Barrel

The aluminum barrel was the glued onto the piston and the tube from the barrel was connected to the other side of the valve so. The entire flow of air now goes as follows: the piston is compressed and the air is forced towards the valve. When the valve is in the closed position the air does not flow through the other side, so pressure builds up inside of the tubes. When the valve changes positions the air flows into the tube on the other side of the valve and the high pressure air flows into the barrel of the gun, propelling the bullet

Step 7: Attaching the Butt

To finish off the project i found a large metal piece of pipe. I hammered it narrower near the end to create the butt of the rifle and attached the other end onto the back of the piston so that the butt of the rifle can sink into your shoulder as you fire



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    10 Discussions


    5 months ago

    could u make a materials list?


    Question 1 year ago on Step 1

    Hi, what kind of valve did you use?

    I think a nice improvement would be a shotgun style pump with a spring-loaded lock pin. That way you could pull it back and keep pressure built up so you don't need to pressurize it just before shooting. Other than that all I can say is wow. Very well put together. (Instructable and project.) I look forward to the syringe model.

    el greeno

    3 years ago

    If you mount the piston the other way round and attach a cushioned pad, you can build up pressure by pulling the gun into your shoulder.
    Mount a handle at the front end for your leading hand to pull in the pain and aim.
    This should help in accuracy and ease of firing.

    2 replies
    el greenoel greeno

    Reply 3 years ago

    Pull in the piston, bloody autocorrect...


    3 years ago on Step 7

    Hi. Please can you give me a bit more information about the piston? What does it looks like and do?


    1 reply

    Reply 3 years ago on Introduction

    its just a piston and i used it to compress air.

    here is the website of the place i got the parts

    i used the female hose coupler, the three position lever, the polyethylene hose, and a piston. i dont see the one i used on that page but they are all fairly similar. AS you can see the stuff is a bit expensive but i made a new version of that using syringes so once i get the video of that edited ill post it