The inserts are a wonderful way to shim your scope without the need to raise your scope too high.
However, the amount of insert doesn't always give you a true representation of the adjustment you will see. There are a number of variables that can affect your result.
with an insert kit, you can tweak any scope for longer distance shooting.
if interested, I have an article on my website in the tech section that can explain how to set your scope up.
Jerry