With the piston you punch a bullet.

When you frontload the cannon the valve must be open, otherwise the compressed air in the cannon tube will try to press the bullet out again.

In the film below an apple projectile is made ready for firing.

Apples are not equally suitable as potatoes, as they weigh too little to achieve long reach (v²-loven).

After frontloading the cannon close the valve.

Then put pressure on the cannon by means of a tire pressure gun (max. 10 bar).

Be patient - it can take some time depending on the capacity of your compressor.

When the cannon is pressurized, you should immediately fire it.

Make sure that the firing area is cleared and that you have a clear view of the target area.

In the film below the boost pressure is 5.5 bar, bringing the projectile out of about 200 m.

Here is another example.