Anyone ever have this go bad on your scope? My shotgun seems to have this problem, shooting from the ground its dead on to 50y but 15 up in a tree stand i have no idea where the slug went. This started 2yrs ago but thought it was just me getting a little too excited, but last year i had a deer sneak up on me and it was a 20 FOOT shot and it was a clear miss, deer didnt move took another shot aimed little higher thinking i went low............nothing clear miss, deer trotted off to about 15y stopped broadside, took another shot aimed 2 inches above its back, and spine shot it. Its an older scope and i think its time to retire it.