Originally Posted by fritz1

Setting back to factory zero is easy, you can do it yourself.
The absolute way to center a scope is to use a mirror.

Step one, place mirror in front of the objective lens and use a rubber band to hold it there

Step two, look through the scope to see two sets of reticles

Step three, move the windage and elevation screws until the two reticles are together and look as if they are one

Step four, remove the mirror and use a bore sighter to sight the rifle

You have now set the reticle back to the factory center.