The valve I use is drawn, the pilot closes and decompresses automatically.
The operation is in two steps: 1- load the .25 caliber lead pellet
2- press the main valve, and you are ready to fire.

I am working with a semi portable tank, and an oxygen-acetylene welding machine piston regulator, adapted for this application.
The firing barrel is 60 cm rifled, and has a simple bolt system.
The air reservoir is a co2 tube, with an internal capacity of 500 cm3, which is filled to a pressure of 800-900 psi. After that, the lower safety valve opens loudly, (and I jump in fright)!
I have thought, as an alternative, to use the 1/4 "steel bb's loading system, locked by gases from the combustion chamber, but I am interested in shooting commercial pellets, to demolish noisy speakers that do not let sleep No hour

