Quote Originally Posted by trajectory View Post
Might be a silly question but I was wondering about how much air a PCP uses v a springer.

For instance if a PCP & springer both produced 11.5 ft/lb & the springer has a known cylinder length & diameter the volume of air behind the pellet can be calculated. With a PCP a 'dose' of compressed air is released from the reservoir but what volume would this 'dose' of air occupy at the same temperature & pressure as the air in the springer?

Does one type use more air than the other to achieve the same result? Any fluid mechanics, physisists, or theorists got any ideas?
The air reservoir volume of my HW100K is about 105cc. At 200bar pressure that's 21 litres of air crammed in there.
From 200bar down to 90bar it gives about 100 shots.
Therefore it uses about 100cc of air per shot.

Springers or rammers probably use between one-third and half that, as measured by swept volume (stroke length x piston area).