SpudFiles

From: http://www.quackenbushairguns.com/bandit_1.html

It says, "The way this gun gulps air, you'll want to use a scuba tank to refill it most of the time. I found our test Bandit used 400-500 psi of air per shot for the first two shots. I felt that four good, powerful shots were available with each 3,000 psi fill. It's possible to get more than 10 shots from a fill, but the velocity of the final one will be down in the 400s."

The gun is charged with 3,000 psi.

After the first shot it is ~2,600 psi, etc.

My question: What does "used 400-500 psi" mean in practical terms for a single shot rifle?

IOW What chamber volume would be required at 500 psi to equal a single shot of the Quackenbush?


BoyntonStu

My question: What does "used 400-500 psi" mean in practical terms for a single shot rifle?

It means that the chamber pressure of 3000 psi has dropped by 400-500 psi. It will drop by higher numbers the more it is shot due to a lower volume of gas remaining in the chamber, and more gas being released to get equal energy.

You would need a much larger chamber than the volume of gas that is released in the first shot is; as the gas in the quackenbush is 3000/lb in^2.
(read the gas laws for clarification).

If you're designing a certain gun, then GGDT is the way to go.