Soup. Another solution to your scope mounting issue is the Burris Ruger to Weaver adapter bases - part #410991. They attach to the rib and you can use any Weaver type ring of your choice. (I chose Burris Z rings.). No need for extension rings as the rear base extends back over the action - allowing for more latitude in positioning your scope. I did this one my son’s #1B .257 Roberts and it worked perfectly.
On my #1A 7x57, I have the Moulds bases that replace the rib and use Weaver type rings. They work great but I don’t believe they’re any longer available. So that’s not much help.🥴
What man, on his death bed, ever lamented, "God, I wish I had spent more time at the office."
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