I purchased a Benjamin Discovery 22 with the pump just before Thanksgiving. The gun had no pressure, and as soon as I began pumping air into the gun, I could hear air leaking from the gun. I emailed Crosman service through the Crosman website. Sally responded right away, then sent me a ups...
Actually you have an error in your formula, it should read as follows: (Velocity (fps) * Velocity (fps) * Pellet Weight (grains) )/ 450240 = Energy (ft-lbs) The Velocity and Grains, must be calculated before you divide by 45020. Cheers, Brian