Correcting Scope Cant

Having fitted a new scope to my rifle, and successfully sighting in at 100 meters, the next step was to increase the range to see how well it would do at 200 and 300 meters. But before going to the longer ranges, I wanted to check if the scope was canted correctly.

Reading as much as I could on the subject, I found various tools that could be bought to level the scope in relation to the rifle.

All of them had a built-in level of some kind, and all put a level across the receiver, or across the scope turret. However none of them seem to first verify if the scope is aligned to the bore. Putting a level across the receiver assumes the top of the receiver is perpendicular to the vertical, and putting a level across the scope turret assumes the turret is perpendicular to the bore. Neither may be true. Or the reticle could be slightly out of alignment with the scope body.

On my rifle, the receiver is higher on one side than the other, so the spirit level method doesn't work.

I came across a web page on

Levelling a scope reticle

that describes how to check for scope cant using a flashlight, so I've used that method and added an additional step in the process to align the mid-point of the reticle and the bore center to the vertical, before adjusting the scope cant.