I just bought a new scope to put on my 870 slug gun and was wondering if anyone had any advice on how to level the crosshairs without any fancy bore site leveler or any specialty tools. In the past, I have just did it by holding the gun still and trying to level it as best I could. Of course, I think it is level and tighten down the mount and look through the scope and it is cock eyed. Any tips would be appreciated. Also, anyone have any experience with Bushnell Banner Duskand Dawn scopes?