RE: One scope for a slug gun and a rifle?
 

There may not be enough eye relief depending on where you mount the scope on the shotgun. The spacing of the rings may be different from one gun to the other.

RE: One scope for a slug gun and a rifle?
 

Your welcome.
Maybe try checking
SWFA at www.riflescopes.com
or www.theopticzone.com
Cabela's has great customer service, but they are a little higher priced.(usually)

RE: One scope for a slug gun and a rifle?
 

Judging by the prices of the Nikon scopes and their reviews it looks most favorable now for me to get one of those for each gun instead of a single Leupold. I'll still have to get my hands on both of them and see which one I like better.