I will always check a new scope by projecting the reticle on the wall with a plumb line. Do this using a flashlight directed through the scope from the objective end, three feet from the wall. With the scope secured, you can check the reticle relationship to the turret using a level. You can also check the reticle's s alignment with the plumb line by dialing elevation. The projected reticle should track with the plumb line.
I use this approach to:
Alignment the reticle to the centerline of the barrel, check action rail alignment, and plumb the scope, I have rarely if ever had to re-adjust my mounts for plumb when verifying by shooting a tall-test target. Scope bases are always bedded to the receiver, and depending on the type of rings, lapped for contact area with the scope tube.
I use this approach to:
Alignment the reticle to the centerline of the barrel, check action rail alignment, and plumb the scope, I have rarely if ever had to re-adjust my mounts for plumb when verifying by shooting a tall-test target. Scope bases are always bedded to the receiver, and depending on the type of rings, lapped for contact area with the scope tube.