Have I been leveling scopes the hard way?

@michael Those definitely make mounting easier, but they don’t work for all scopes or scope and ring combinations. Sometimes the rings are too high or turrets or knobs are in the way. Good little tools to keep handy though. 

The pictures aren’t showing up for me for some reason but I gather from Dave’s comments that we are talking about a wedge system like the Arisaka. Such an approach is a great time saver and the result is good most of the time, but do bear in mind it relies on over half a dozen assumptions about the perfectness of various machined and/or assembled features. For an experienced person like you, I expect you would soon recognize it if the reticle is not aligned properly to the bore, but it could be a source of confusion and frustration for others.

Bought mine from the original maker some years back. I have found it to be very accurate and when it is off it is only off by a little. I would have to agree with nervoustrig with the points he brings up though.

https://www.midwayusa.com/product/1021763218

I have never used any tool, but it is very important to use the reticle adjustments for fine zeroing only. So I mechanically center by turning all the turrets end to end counting the turns. I then divide by 2 and center the adjustments. Then I shim the mounted rings with brass shims to achieve target center at say 20 yards and use fine adjust for zero from there.

I notice that Meopta scopes have a line on the underside that matches a mark on the mounts they have available that orients the scope to the mount to the rifle. 

Not saying anyone is doing it wrong and I’ve tried a dozen different ways and means. This was highly recommended to me by a well know FT shooter who shall remain nameless as I haven’t been told I could use his name. 
Its available from Brownells and it aligns the vertical reticle to the vertical axis of the bore. It took what I believed was a perfectly aligned scope using a similar product and found It’s about a 2° can’t error in the vertical. 
It solved the mystery of why I was high and right from my zero.

I use these wedges all the time and have found them to be a great time saver! But, I always go back and double check using a plumb bob and spirit level. I haven't found the need to adjust any of my scopes after using the wedges. there are considerations regarding the levelness of the rail, whether the reticle is perfectly vertical within the scope, and all sorts of other assumptions, as mentioned by others. I would think those imperfections would be found, primarily, on low end scopes. Higher quality scopes shouldn't suffer from some of those shortfalls and, if they do, they should be able to be returned for a properly made replacement. 

Regardless, if you choose to use these wedges, I would always recommend using whatever trusted system you rely on to double check that things are true. That being said, I just picked up another set because I've been reaching for them so often, lately. 

https://youtu.be/xdihirxvas4

This one must be the deluxe version.

TXTactical Scope Leveling Tool, Scope Leveler, Scope Leveling Wedge https://www.amazon.com/dp/B096FGVK7Y/ref=cm_sw_r_cp_apa_glt_i_T1D80WNQ63ZTGFT641HH

 I just use a set of feeler gauges... Then fine tune..

Not saying anyone is doing it wrong and I’ve tried a dozen different ways and means. This was highly recommended to me by a well know FT shooter who shall remain nameless as I haven’t been told I could use his name. 
Its available from Brownells and it aligns the vertical reticle to the vertical axis of the bore. It took what I believed was a perfectly aligned scope using a similar product and found It’s about a 2° can’t error in the vertical. 
It solved the mystery of why I was high and right from my zero.

Click to expand...

Oh that is so cool!!! Gonna have to get that! There will be zero mistakes with that tool. Thanks for the tip.