the .22 trajectory uses so much of the reticle a zero distance is not really important. I would setup to have a definite aimpoint to shoot through the 15mm's then just map the ret to see where the rest land. The actual distance needed to zero at to do this will also depend on your scope height, where higher is definitely better!
HFT, for people with only 2 buttucks!
VooDoo TwoTwo The next chapter.