camp 13 is right. I got inserts, but not the OFFSET inserts. The ones they came with are zero effectinserts.

There was a guy in front of me at BassPro that had the exact same problem I did. He had the SAME receiver mount plate that I have, and some scopes would work on it and some wouldn't. But his Mossberg was newer than mine and tapped for a different mount on top so he didn't need the one that bolts to the sides. So he took off the mount plate and went with the other mount and is now doing fine.The mount plate I have (and that guy HAD) is see through so you can use open sights if you want. I think this elevation contributes to not being able to sight mine in without inserts.