Reliability stacks, the more parts, the more often the machine stops. Theoretically, a spool valve like you built with one moving part should be very reliable. However, you probably need to look into how the seals on DCV's are done, O rings rarely like to move past porting, having the o-rings seal i...

I used to be the same way. I still rarely use it these days, but it's the unfortunate truth.

Very nice project! Since we're talking about rifling, have you seen how people are using "electrochemical machining" to rifle barrels from steel tubing?

Pretty good for a nailgun! :p I have a few recommendations for the next one, though. That chamber is pretty massive for a 1/2" barrel. If you were to use a smaller pipe size for the chamber (say 40-50mm) you could probably find some better pipe which is either rated for pressure or will hold up bett...

ITWOST: Got some new camera gear and figured I'd take a closer look at one of the "good" piston valves I've made recently. https://youtu.be/SVZjXHcsJnk There's a lot more work on the completed project because I want to do silly sh*t, but another small anecdote: you ever head of FOGBANK ? It's some s...

Update on the current project and a little sneak peek: still lots to do (polishing valve seat, rebuilding piston to track more cocentric, some funny stuff with the barrel, a way to aim more better), but I managed to put a hole in my box spring with some supposedly "low power" testing and a plastic 1...