There are no gears made in that ratio. Check post #8 in this
http://www.airsoftcanada.com/showthread.php?t=132660
Do the math and then you can tell us the ratio of these oddly labled gears.
Airseal and inner barrel length will make a difference in the fps across different setups with the same spring due to of course airleaks and also cylender to barrel matchin in volume. Bigger cylender shorter barrel equals wated air and lowwer fps.
An example is a VSR 10 bolt action is optimized for a 500mm inner barrel.
The gspec comes with a 330mm the same build with only the inner barrel shorter looses 100fps (500fps on the 500mm and 400ish on the 330)
By drilling a hole in the cylender to shorten it (read match the volume to the shorter barrel) the fps can be corrected to 500fps on the 330mm inner barrel with the same spring and and piston and hol up