I have to agree, the DNZ may not be tacti-cool but there are no rings that will get the scope lower on the Tikka. Toss that Barska or sell it for as much as you can get, it may take a few cycles on eBay but it will sell eventually.
You would be better off with a used Leupold VX3 then anything made by Barska. If you are looking for something budget and along the model you currently have the Leupold Mark AR mod1 are decent. Just dont get anything with large windage knobs as you will have difficulty ejecting the 7mag cases.