Gunskayaksdrones shows this green laser bore sighter that you can use for your airsoft gun. This will help you zeroin your sights and optics without needing to go to a range and do it the traditional way of shooting then adjusting... "New purchase just arrived from Ebay. It’s the Golden Future bore sighter. The laser is green. It can be used for handguns, rifles, Airsoft measuring from .22 to .50. The smallest adapter fits my 6mm Bore on my ICS Transform4 perfectly. By screwing in the adapter, you widen (enlarge) the end of the adapter. By loosing the adapter, you make the diameter smaller.

Tighten it until the adapter is snug. You don’t want the bore sighter falling out but you also don’t want to get it too tight and causing it to not fit properly."