Might I enquire as to what base you are using? I've gone through a number of set ups with questionable results. As of late I've found a setup that works. First off, stay away from steel bases. Aluminum can be sinched tighter because it compresses more. I've found Millets rings to grip glossy scopes very well. If you're bending rings try 3 rings per scope.
If you have 2 bbls that need scopes, buy 3 sets of millet rings and split the odd ones. This works great for me.