You don't move the "speed ring" for longer shots. Set your speed ring to approximately 325 for your Vortex (I believe) then zero it for 20 yards using the crosshair. The first triangle below the crosshair is (approximately) your 30 yard aimpoint. The next is 40 and the last is 50. Zeroing your scope for more than 20 gives you a higher point of impact at 50.