Doesn't make Sense

[JohnKielly]

Is it possible that what you have is a standard single piece scope base or rail with 30mm rings on it, that is, you don't have an inclined rail at all? It's easy to check with a verniers. From rail top to round action bottom will be the same distance along the length of the rail, give a thousandth or two.

If that was the case, then it would be entirely credible that you could get to an 800 yard elevation with the scope's adjustment as you would theoretically need 22 or so MOA up from your 100 yard zero for 800 yards & another 10 to get you to 1000. But your scope only has 22.5 MOA off mechanical centre, so if you haven't got an inclined rail at all as I suspect, then you were particularly lucky to get onto aim at 800 yards. 1000 as you found would be impossible.

 

[memilanuk]

That's 20 up and 20 down from the middle. I would run a 15 MOA base and MAYBE you will get close to the 40.
It actually makes sense.

My NXS 12-42x that I used for the 2009 FCWC has approximately 45 moa elevation, and about 35 moa windage. Granted, we used 155.5 Fullbore bullets @ 2950-3050 fps, but still.

With a 30 moa Farrell rail, I would be able to either just barely get a 100yd zero, or sometimes have to settle for a 300yd zero - depending on the barrel. The nice part was that with a trajectory of about 28-29 moa drop to 1k, that put my scope right at, or very slightly above, mechanical center when I was shooting @ distance... meaning I had as much windage as possible available to either side. And @ Bisley, we needed it!

 

[Geno C]

The question of how much elevation is available once zeroed at 100 wasn't answered. That's the biggest thing. All barrels and actions are not equal.