I have a Impact MZ I had a Vortex scope on that shot fine. Liked the scope so much moved it over to my rifle last season and killed out, so the MZ sat unused. This year no luck so far so bought a Vortex Diamondback and mounted it on the gun. Keep in mind I did not touch the mounts, only removed the top of the rings to replace scopes. So this new scope hits so low that with elevation maxed out the point of impact is 10" low at 20 yds. Remounted and the same. In forty years of doing this this is a first for me. Any thoughts? Thanks

Scopes can have different internals whereby having one mounted properly may not relate if you change to another, but that much divergence is hard to believe. Could it be the first one was set up near the edge of its adjustments, making one still centred look bad?

I understand different Vortex models are made in different countries, some dubious, but that alignment of one could be that far from another is beyond belief. I don't suppose the direction of zero movement could be opposite in these models?

I don't suppose an inverted 20 moA Piccatinny rail could have anything to do with it?

My last thought on this would be that since all image-movement scopes are accidents waiting to happen, an erector spring may have broken and then wedged on the wrong side of erector tube.

I have a Vortex Diamondback mounted on my Marlin XS rifle and it is centred well on the adjustments when shot in. The Marlin XL and XS rifles were sold here with a Weaver style single piece base already mounted for a scope.

As Sambarman has suggested maybe your Diamondback is faulty. Centre the adjustments on the scope you have removed and refit it in the rings then bore sight and see how far out it is with the centered original scope. I assume you bore sighted your Diamondback when you fitted it, you should have picked up the 'miss-alignment' then before shooting the rifle.

Any update on the scope problem?