I had a strange thing a while back. A late model Leupold

scope, really too much scope for the gun, but I need it for precision at distance. It's on my .416 Rigby BRNO 602. The BRNO has integral scope bases on the receiver and I am using CZ rings that worked fine on other scopes. I ran out of scope adjustments still needing 16" elevation at 100 yds.!

It's been a while I've had issues like this, lastly with a 10/22 Ruger. They seem to have chronic issues like this. I made some brass shims for the front ring base, to see if I could slide the few thousandths spacers under the mount and it still clamp as designed. (I actually made them from flattened 7mm-08 case walls on a split casing) The spacers should allow for that much movement and more. The tongue in cheek base number is 0.001" = 1 MOA, but I don' think that is in stone. There are many more mathematical factors involved. I've got about 20-22 thou of shimming with two pieces I'll custom fit. I know all the fretting of torquing the tube, lapping the rings and such.

I'm still going to investigate to see if anything else may be factoring in the lack of scope adjustment in elevation. Swapping scopes again would also be another option.