Make an Airsoft Machine Gun From a Soda Bottle





Introduction: Make an Airsoft Machine Gun From a Soda Bottle

Toy Challenge 2

Finalist in the
Toy Challenge 2

Several months ago I posted a project showing how to make a 'cloud' BB machine gun with a built in air supply out of PVC. That project, while very entertaining, cost $50 in parts and took several hours to complete. More recently I have resumed experimenting with BB machine gun designs with the goal of making them as inexpensive and easy to build as possible. The model that is made in the above video can be assembled in under 5 minutes, uses only four parts, and costs a total of about $15. If you have not seen my previous BB machine gun project you can take a look at it by clicking This Link.

This airsoft gun is a bullpup design, meaning that the pellets enter the barrel from behind the trigger. The machine gun works because as the bottle is pressurized the only way for the air to escape is through the barrel. That escaping air sucks pellets up and out with it like a high velocity vacuum. The rate of fire that can be achieved through such a design is spectacular, in excess of 50 rounds per second. The estimated FPS using a 6" long barrel is 250 when the bottle is fed with air at 100 PSI. If a longer barrel is used much higher velocities can be achieved.

Parts Required:
  • Soda Bottle
  • 7mm x 6" Automotive Brake Line
  • 1/4" Quick Release Air Compressor Fitting
  • Air Compressor Blow Gun

  • Drill & Drill Bits
  • Hot Glue Gun
  • Air Compressor

The only downside to this particular machine gun is that it must be plugged directly into an air compressor line to fire. Fortunately, there are several modifications to this project that remove the need for a constant connection to an air compressor, such as a backpack mounted air tank. A flamethrower style backpack tank version will be featured in my next video, in addition to a modification that requires no access to pressurized air whatsoever, and will cost even less than the featured model.

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Until next time,



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    So I made one this morning using a root beer bottle and a hard plastic straw that was the right size for the bb's, and of course my air compressor. Even with the scavenged parts, this is SO MUCH FUN!!!! Thank you.

    I made this gun for my airsoft loving friends birthday. I put 2 guns on a camera tripod. It was by far the best gift. Thank you for this great instructable

    15 20:06.jpg

    I'm doing something similar- I'm just using canned air instead of a compressor so I can easily take it to wars. My main worry is how long the gun will last before it breaks due to wear-and-tear. Should I reinforce it with wood to keep it functional, or should I remake it, but use pvc instead of the bottle?

    just finished it- thanks Nighthawk for the instructable! I'll post one of my modded ones here :)

    I love this and will build with with my nephews . Thanks for helping to get them excited about making things.

    I love to hear people wanting to help kids get into creating things. Have fun! Don't forget the safety glasses!

    NightHawk- I'm wondering as to the placement of the air blower. Does the position matter? Thx

    We did use the safety glasses and it worked out fine.

    Um, would you possibly be able to post a link to where you got the blowgun? I cant find that type anywhere...