I have this taped to my workbench.

v = sqrt [(fpe * 450240)/wt]

v = velocity in fps, wt = pellet weight.

Take the highest fpe you want to work with 19.9 or 11.9 (or whatever), multiply that number by the common factor 450240, divide the result by the pellet weight in question and take the square root of that result and Voila!

19.9 x 450240 = 8959776

8959776/10.5 = 853312

And the square root of 853312 = 923.75 fps

Same deal with 12 fpe guns. Figure up the desired fpe for anything, 20, 12, 15, 100, whatever. The variable is projectile weight.

***********************************************

Map to the FT Park>

http://maps.google.com/maps?hl=en&q=1150%20Evans%20Bridge%20Road%2C%20Heflin%2C%20AL%2036264