Rifle Scopes The importance of correct leveled scope.....or not...?

[rideHPD]

If anyone has ever sighted in an winchester lever action with a side mount scope, or an SKS or anything with a scope that is mounted over the side of the rifle, then you probably understand what Spuhr is talking about. If you could extend your vertical stadia line down to the bore and it does not intersect the center line of the bore, then you are asking for trouble unless you only shoot at ranges where the deviation does not matter

Or if the vertical stadia of the reticle does not intersect with the bore, and you then level the scope to the horizon. This turns the system into an offset scope mount in effect, which can be seen to have minimal effect as long as the scope is level.

 

[Pinecone]

If the vertical stadia intersects the bore on a 94, then you will have to cant the rifle to make that stadia perfectly vertical to shoot on target, IF YOU DIAL OR HOLD FOR LONGER RANGES.

If you are only shooting within the point blank range and using a center hold, none of this matters.

 

[JL]

Direct translation from FinnAccuracy pages:

If scope is installed 1 degree off from actual vertical action-bore line, this causes horizontal error which is sin(1)=0,0017 * used elevation on turret.
It POI shifts left from true vertical line, reticle angle is counter clocwise and vice versa.
With 20mrad elevation, error is therefore 20mrad * 0,0017 = 0,035mrad, so POI is 3,5cm/35mm left or right from true vertical line.
Actual reticle angle vs scope housing/mechanical movement error seem to vary between 0,25-1 degrees with typical "better" manufacturers. Only way for normal user to confirm it is to arrange test shoot.