dispatch 510...
Mine is another vote that your scope should be just fine well beyond the 80yd range.
Parallex error is really the only thing that can go wrong. A simple definition is that the crosshairs really are not aligned on your target. Is kind of like putting a stick half way into a pool of water and it appears to be bent when it really isnt.
The simplest test that I know of to detect Parallex error would be to place the rifle on a surface where you could push and pull on it a few inches all while viewing the crosshairs.
If the Parallex error is present, the crosshairs will appear to jump dramatically at some point during this travel. You can try this on objects from 50 to 100yds, 100 to 200yds, and so on.
I really doubt that you will find a problem with yours.