The fuel (propane or mapp) enters the chamber at rear,
It pushes a (light weight) piston forward against fairly weak spring pressure.
As the piston moves further, a small port hole (equipped with check valve) becomes exposed and the pressurized air/oxidiser enters through that port, pushing the piston all the way forward.
The piston could be connected to either a bolt (blow-forward bolt for loading, or the entire barrel with hole at top for mag feed)...
At first I was thinking the moving piston would close a switch for ignition,
But now am thinking a seperate electrical switch (triggering) could be used for this.
For exhaust, I was thinking that a gas assist similar rod could push a check valve and vent the chamber(?)....
It will probably be built from 3/4" brass nipple pipe.
Any thoughts on that /replies appreciated!
Thunder.... 8)
(too bad I had not the time for the contest)
