For 20+ years,
I used to manually shim my rifles if/when I ran out of elevation when shooting longer distances..
Yes, shimming will work, but as mentioned, if you're not careful or know how, you can ruin your scope, throw things off, etc.
Adjustable mounts and rings work Great for this though..
I didn't expect to have to get / use them, but, I got a few new guns and scopes, and instead of shooting long range,
I've been stuck inside shooing at close [10m] range. The same exact thing applies - Elevation clicks run out.
[The pellet can't hit it's max height in its curve at the given distance]
Hajimoto suggested I try the FX No Limit rings, I did, and they worked Flawlessly! I have two sets now..
I get multiples of my favorite scope, so same with rings, etc. to keep everything 'the same' w/ each rifle setup..
Anyways, as with other adjustable setups, the front and the rear will pivot..
This will let the entire length of the scope tube pivit [angle] with them - and keep everything true and in-line..
There will not be any misalignment causing spots to pinch/tweak when tightened into position..
No uneven stress anywhere.. And that is what is most important - so not to throw things off or damage the scope components..
+1 and +2 from Me for the FX No Limits.
I've swapped those two scope/ring combos around between 5 different PCP rifles now, and perfection each and ever time.
Without them, I wouldn't be shooting.

Sam -
[Edit] Oops, itchy trigger finger hit the submit button too fast..
Another BIG piece of advise - and again, this was mentioned before and probably will be mentioned again and again..
TORQUE SPECS DO MATTER. Make sure that when you're adjusting / installing your optics
that you're using the Correct / Recommended torque value from the manufacturer for the given components!
They will differ depending on design, materials, etc.. There's no magic number..
It's always better to be safe than sorry.