Introduction: Make an Airsoft Machine Gun From a Soda Bottle
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About: I like turning boring things into awesome things! Usually on video.
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:
Tools:
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.
Please remember as always to share this article with others on Facebook and Twitter, and if you really want to support my projects, submit this article to other sharing sites sites such as Reddit and Digg. To be the first to know about my new projects you can also subscribe to my YouTube Channel.
Until next time,
-NH
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
Tools:
- 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.
Please remember as always to share this article with others on Facebook and Twitter, and if you really want to support my projects, submit this article to other sharing sites sites such as Reddit and Digg. To be the first to know about my new projects you can also subscribe to my YouTube Channel.
Until next time,
-NH
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80 Comments
5 years ago
Is there anything i can use to substitute the brake line?
7 years ago
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.
7 years ago
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
7 years ago on Introduction
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?
Reply 7 years ago on Introduction
just finished it- thanks Nighthawk for the instructable! I'll post one of my modded ones here :)
11 years ago on Introduction
I love this and will build with with my nephews . Thanks for helping to get them excited about making things.
Reply 11 years ago on Introduction
I love to hear people wanting to help kids get into creating things. Have fun! Don't forget the safety glasses!
Reply 7 years ago on Introduction
NightHawk- I'm wondering as to the placement of the air blower. Does the position matter? Thx
Reply 10 years ago on Introduction
We did use the safety glasses and it worked out fine.
8 years ago on Introduction
Um, would you possibly be able to post a link to where you got the blowgun? I cant find that type anywhere...
Reply 7 years ago on Introduction
go to a hardware/auto parts store
8 years ago on Introduction
Awesome toy! I couldn't wait for the auto parts store to open, so I substituted the brake line with a 9/32 brass tube 12" long (K & S part #132). I used a plain rubber grommet to hold it in place....no glue required. These are available at most Ace hardware stores and/or hobby shops. If you think about it, the air pressure is only acting on the surface area of the end of the tube to push it out....a very small area. The most ingenious part is that the incoming air agitates the ammo and keeps it feeding the barrel....no bends needed. I rigged up a leftover Ballon Time helium tank for the air supply. I had to drill out the check valve to get it to accept air....great fun!!! I found the blow gun at Harbour Freight. This a great harassment tool for predators.
John
8 years ago on Introduction
will it take down pigeons?
8 years ago on Introduction
We can't find a straight
8 years ago on Introduction
awesome post!.
I am working on a diy shotgun at worldpremierairsoftcenter.com
also doing a diy sniper rifle and bunkers = )
8 years ago on Introduction
tried it on my friends it worked like hell...... :)
8 years ago on Introduction
it is epic
9 years ago on Introduction
Made it and it works like... like... like a bought one!
9 years ago on Introduction
If i used a co2 bike pump and plugged it into the blowgun in replacement of the air compressor, would it work?
9 years ago
If you used a longer sized bottle, would you need a longer sized brake line to accommodate?