Does the device assume that the reticle is true..ie not canted ?
I think one would have to assume the reticle to be properly aligned in the scope. FOst had a new VX-6 with a canted reticle that he sent back to Leupold. They fixed it and he now has it.
This tool will greatly assist in aligning the reticle with the gun. The alignment of the reticle in the scope is another matter.
