If I play around with Lloyd's spreadsheet, I can find a set of numbers that gives the following results.... very close agreement with your results, and ones I have had previously....7.5" - 435 fps10.25" - 476 fps12" - 496 fps14.5" - 517 fps18" - 538 fps24" - 559 fpsThe valve dwell required at 850 psi (~70*F) would mean that it is still open when the pellet exits a 10.25" barrel, but closing just before it exits the 12" barrel.... I have never tried a 12", but there is a significant difference in noise between the 10.25" and 14.5", so that would seem about right....Bob
Hi All i would like to see this test done on .177 barrels in the 18" and 24" at least.Don
A 16" barrel 177 on a stock 22xx co2 gun will be in the low 600s with 7.9s IIRC.Convert to pcp and it'll do in the 900s.