His rifle and scope is easy to square up. First set up the rifle level. Use a small torpedo level under the flat part of your forestock. Once the rifle is level side to side, place the level on your top turret cap. With the rings loose, rotate your scope inside the rings, without moving the level rifle, until the torpedo sitting on your turret cap is also level. Begin evenly snugging up your ring screws each a little at a time and keeping that torpedo level. Use a torque wrench to set the specified load - I don't use a torque wrench.
I find I need my scope typically set as close to me as possible to get a full view/picture through the scope. Cheaper scopes tend to show me a dark perimeter ring at the top power settings. The eyepiece focus can be set to provide some clarity.
Others will likely offer up other ways to square up your scope. I make this work for me without special tools.
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