I agree with all that you say there @oldAG but I think you can make a finer adjustment when it is lined up using a plumb line at distance and your scope adjusted in the same way as it would be taking a shot at that distance.
@Gwion I use a level across the top of the rail. However I am not sure it is that critical how the rifle is lined up. It is really about the scope retical being vertical so that the turret adjustments to the retical move the POI in the true direction.
Wrong. So wrong.
If what you are trying to achieve is accuracy, without cant, at extended distances then it is critical that not only is the reticle absolutely vertical, but that the rifle is also set up truely verticle. Rifle/action is done by placing a bubble level across the action, scope rail, or other known horizontal plane. Then, the scope reticle, or tang sight elevation staff, is aligned vertcal. There is NO point in aligning the reticle vertical if the action is not also vertical.
Imagine setting the scope up so that the reticle is rotated 45 deg clockwise. If the scope is maintained “level”, a shot at say 50mtr will be ball park. Maybe even zeroed at that.
But at, say, 500mtr the shot WILL be left and low. You not only have to adjust elevation but also windage. Similarly, rotated anticlockwise, the shot WILL be right and low.
It is ONLY when the scope and actual trajectory are aligned in the vertical plane that (excluding wind) adjustment of elevation is required.
I also place my level on the rail or flat of the action… when possible.
However, not all rifles have rails or flat spots on the action…
Im not talking about having the reticle at 45 degrees. I said that this must be vertical and the bubble level that you permanently on your gun keeps this vertical. so when you wind on or off elevation it keeps it in the vertical plane. However which way the action points under it is irrelevant. The rifle for all intensive purposes is round it doesn’t matter which way the stock is pointing.
The gunsmith may have indexed the barrel to get the natural bend of the rifle to be in the vertical so it is more easily disguised in the drop. But that bend is constant and can also be compensated by windage adjustment. The only purpose of the stock is for holding the action and most importantly managing the recoil to keep that to a minimum and parallel with the barrel. Not kicking up or sideways like some designs do.
sungazer-Scope mounting (and rifle levelling))
Im not talking about having the reticle at 45 degrees. However which way the action points under it is irrelevant. The rifle for all intensive purposes is round it doesn’t matter which way the stock is pointing.
The only purpose of the stock is for holding the action and most importantly managing the recoil to keep that to a minimum and parallel with the barrel. Not kicking up or sideways like some designs do.
My post said “imagine setting the scope up”, only to provide an extreme example. What I said remains true. Which way the action points is very relevant.
I agree that IF the scope and rifle trajectory are aligned in the vertical plane, it will not matter that the action/barrel assembly is not “vertical” in the stock. Shooting with a canted stock, if that’s how you want to make it fit your shooting style, is not a problem at all.
Maybe one of us is not getting their thought trajectory onto the forum accurately (sorry about the pun). For a good explanation, go here: - https://www.accurateshooter.com/optics/canting-effect-on-point-of-impact/