I'm putting a Sightron 6-24x42mm on my CZ 452 Style and have never done this before.

I put the Brooks 11mm-to-Weaver high mounts on the dovetail, no problem, tighten the screw and I'm done.

Then I put the Burris Signature Zee rings #420532 bottom half into the mount, put the screw through the side and tighten. Put the bottom half plastic insert in, then the scope, then the top half insert, then the top half ring and tighten the torx screws.

Problem is that there is 2-3mm play in my scope from front to back. The rings are shifting on the mounts which can't be right. What did I do wrong and how do I correct this?

Thanks guys.

Sounds like you either didn't get the right adapters and the the bases aren't actually standard Weaver size, or you you didn't mount and tighten the rings onto the bases correctly. If you have a friend with more experience mounting scopes, you might have him/her take a look at it or at least talk you through it over the phone. Mounting a scope on a gun you want to compete with, having never done it before, might not be the best idea. Have you at least seen it done before? Might be best to let a gunsmith do it and just pony up a few bucks to get it done right.

The screws that attatch rings to bases just were not tight enough. You have to bear down on 'em more than I thought. That's what I get for bein' a noob.