The chamber's volume is 31cm^2, and the pipe is 2cm inner diameter, and 2,2cm outer diameter. When I decided to use syringe fuelling I sealed the cover, and made a small hole for fuelling.

Hi again guys, I followed your advices and removed hose connections, now I have a solid pipe coming from the chamber to the barrel. I also tried to reinforce the cover with a metal plank, but now the pressure bent metal corners of it. I then tries syringe fuelling with no luck, my calculations tells...

Thanks for feedback, guys! When you are saying hose connection, you mean pipes connected to each other, or the hose I used to connect combustion chamber and the pipe? I can see, how having funnel at the end of combustion chamber would help, but I never thought it is SO important. I'll build a new on...

Hi guys, here is my first spud rifle. I made it using the remains from countryside home construction. It fires well, but I have a problem - the cover of the blast chamber is always cracking after a few shoots - it happens because it is held by 2 bolts and metal frame, and bolts are tearing the cover...