I had a 6500 and it was crap. It you changed the power setting the zero would move. I confirmed this on a bore sighter. I hope yours doesn't have this feature too.
I have the 4200 6x24x50 30mm tube and the 6500 4.5x30x50 30mm tube both have tactical turrets both are awesome scopes slight nod goes to the 6500. If the glass isnt clear in either scope send it back. Would not hesitate to buy another... for the money they are still my choice.