Gas Types & Any Power Increases ?.....

[Rex Havoc]

I fly rockets and in the liqued fuel rockets the lower echelon use what are called blow down pressuerized tanks. No pumps, helium is in its own tank plumbed to the oxidzer and fuel tanks. They use helium because the molecules are smaller that anything else but hydrogen but I really wouldn't recommend using hydrogen as a pressurant due to the fact it would throw flames from high compression ignition, maybe evening causing the gun to burst. Helium is inert but you'd have to be very careful not to over-pressureize the gun. Blending it with other gasses would lessen the effect due to the larger molecules so as far as a gas goes straight helium would be the way to go IMHO.

[7624452]

Try this.
http://www.rocketryforum.com/

[BDS]

"Air soft gas"... do you mean de-natured Propane or green gas?

[Rex Havoc]

Try this.
http://www.rocketryforum.com/

I have 1400 posts there