I just had to break out my rusty algebra skills. With 44 cal lead (if all is correct) I would need at least 235 fps to be at or nearly 15 ft/lbs. I had to look up the equation. Energy = Weight (in grains) times Velocity Squared divided by 450395 (fixed constant) Then i had to find 44 cal weight in grains. 44 cal = .429 inch ? Used the ammo chart in downloads. approx 122 grains not quit 11 mm? Any suggestions or corrections? Balls are from a do-it slingshot pellet mold. Edit: mold info says 1/4 oz and that is only equal to 109 grains. Back to my rusty algebra.