Tippmann C-3

The Tippmann C-3 was the first propane powered paintball marker. It operates on a unique system Tippmann calls 'Propane Enhanced Performance'. The name 'C-3' may refer to the chemical formula of propane, C3H8.
Operation.
While traditional Paintball markers rely upon the expansion of an inert compressed gas (namely or air) for Paintball propulsion, the C-3 utilises the energy released in propane combustion.
This is a simplified explanation of the C-3's firing system:
The C-3 operates on a closed bolt system. As the pump is pulled back by the shooter, the bolt moves back to allow one paintball to fall into the breech.
As the shooter returns the pump to the forward position, completing the pumpstroke, propane is drawn into the combustion chamber. The bolt also moves forward, sealing the breech, and bringing the paintball into the firing position.
After the pump stroke, the shooter pulls the trigger, causing a spark and igniting the propane. The resulting expansion of gases forces a piston forward, which in turn compresses air behind the ball, propelling the paintball forward.
Advantages of Propane.
Performance - Since combustion releases a great deal of energy compared to expansion, the C-3 is able to get up to 50,000 shots from one 16oz tank of propane, over 60 times the amount from a comparable or compressed air tank.
Safety - The fuel is a standard 16oz propane tank, which is stored at about , a much lower and safer pressure than the for or for compressed air.
Price - Disposable 16oz propane tanks are readily available at discount, grocery, and hardware stores for around $3.00 and deliver approximately 50,000 shots - a single disposable tank may well outlast the marker. In contrast, reusable tanks cost $5 – $25 and compressed air tanks $35 – $200, delivering 300 to 1200 shots per refill.
Simplicity - Due to it being just that, a propane canister, one can make a "remote line" using a standard propane hose.
Consistency - Propane is more consistent than , as the amount of energy released is independent of ambient temperature.
Disadvantages Of Propane.
Heat - A large amount of waste heat is produced. This is the main problem with creating a self-loading combustion powered paintball marker.
Further developments.
 describes a semi-automatic propane-powered Paintball marker. Operation is similar to that of a reversed C-3 mechanism, with the pump being replaced with a return spring and heavy piston. Pressure produced from the ignited propane pushes the piston forward, which opens a poppet valve and releases exhaust gases into the barrel. The piston continues forward under its own momentum, bounces off the spring and returns to its starting position.
It is unlikely that the self-loading version described in the patent will be produced, due to excess heat production.