There are all kinds of DIY projects to fill a weekend, but have you ever thought about building your own gun? You never know when you might find yourself in a post-apocalyptic world, and building a gun could be a useful skill.
Let's start with a simple air gun:
If you want a little more portability (and a little more air capacity), you can put the pump on-board and run it into a two-liter bottle:
A few tips for optimizing your gun's design: Air gun tips.
If you want to take it to the next level, add a trigger, a bolt and a laser:
If you don't like the idea of using air as a propellant, you can use stretched rubber (aka a slingshot) as your propellant instead:
On a smaller scale, here is another take on rubber propellants: How to make a simple yet powerful gun.
Magnet power is another possibility. After you watch that video, you can consider putting the principle into a pistol format:
Or a rifle:
Another propellant that DIYers use is the common firecracker. The simplest possible implementation is seen here:
It is easy to extrapolate from there. If you jump into YouTube or Google looking for "firecracker guns" you can find all sorts of stuff.
One final propellant to consider is electricity. For more info on this approach see: Build your own Gauss pistol
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