I have mounted many many scopes over the years used Burris mounts Leupold mounts weaver mounts
basically mount, level, set eye relief , tighten bore sight then sight in done
if I was using Leupold Rings I would use the back screws to set windage
i have shimed rings in past so as not to use up scopes internal adjustments

Ok so now I just finished a custom built 284 i went with a shelin barrel instead of my usual Shaw and I topped it with a SWAROVSKI so anyway did not bore sight and forgot screwdriver for Leupold mount screws windage was way off no big deal came home counted clicks in scope and reset scope to center dug out bore sighter reset scope but I noticed that my rear mount after bore sighting is not pefectly centered. Well I looked at two others I have and 1 has similar results now that rifle shoots great but never shot it past 200 yards.
So st that point I stopped ordered alignment bars and a lapping kit. No now I centered the rear ring used a”ingment bars and al was good I then lapped it anyway just to take of rough spots rechecked and good mounted the scope put bore sighter on and it was off so I had to adjust rear mount which leaves the rear mount .022 off center

guestion 1) to me this means scope not square to barrel? And it will effect long range shooting?

Question 2) SWAROVSKI recommends putting glue in bottom of both rings ( a rubber cement style glue) anyone ever hear of this ?
Thanks
chuck