Good luck…and let me know what ya’ found out.
But, as Ramos said, some are easier than others.
- To me, what ever is used as the base of your endeavors [work bench, table, floor or whatever] has to be level.
- After that, then what ever cradles the rifle has to be level.
- After that, the reference part of the rifle has to be level whether it’s a flat spot on the receiver, scope base or what have you.
- After that, what ever is the reference point on the scope has to be level.
- Oh, before I forget, you need to have a decent and repeatable level.
It may sound like over engineering or stacking BB's but I’m just trying to point out all of the variables and just because one doesn't see them doesn't mean they aren't there.
I’ve tried several gadgets but lately I’ve settled on the Wheeler level system. It’s not the level-level-level that came several years ago but a more recent version that has heavier and better grade levels with one that fits on the barrel.
I’ve also started putting levels on the scopes to hold the rifle level while shooting. Hey, no need in having a perfect leveled scope & rifle combo only to cant it out in the fields when shooting.
When I finish I use a horizontal and vertical reference and run the turrets from top to bottom and left to right checking for any signs of walking of the references. On this note, this where having a good quality scope comes into play. There are many stories out there where the scope doesn’t track true.
While this may sound like an exercise in futility, it does work and has served me well and like everything else, when you get the hang of it goes pretty quick.
When all of this is done and you're sighting it in and settle in on one of those .250 x .250 MOA groups, always...always take the time to do the box test and as previously mentioned, make sure you're not canting the rifle while doing so.
Sorry for the long wind...HTH