David Ye’s clever BB gun is the bane of apples and fairly easy to make, judging by his great video.
I got bored and decided to make a BB gun using my air compressor. The secret sauce is a one way valve that blocks air from the firing chamber but allows air in the other direction to rapidly propel ammo into the gun. This allows me to tube fed BB’s, even when the gun is inverted. It’s also much faster than gravity feed versions. Watch the video for some action shots and how to make the valve.