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?
yeah there's a big difference - plenty of posts on this forum about the bore and stroke of tx200s and hw97's, something like 26mm bore x 80mm stroke, about 40cc of air.
A 12 ft PCP would need something like 3 times that much air, maybe a bit more for a .177.

Note that doesn't mean springers are necessarily 3 times more efficient than PCPs though!

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