I would suggest there is a problem with this scope.
I have 2 new model Nikko big 60 scopes fitted to my 2 EV2 rifles.
Both of them are crystal clear on 50 mag when focusing at 55 yds.
So clear i can see the threads of the string that is attached to the target.
Several of my FT club shooters use these scopes and there has been no problems focusing at 50mag on the long range targets.
If you need to turn the scope down to 35mag to focus at 50-55 yds there is a problem with the scope.
Hope you can get it sorted.
Tel. ( Hereward FT club )
The impossible is done right away,miracles take a little longer