As a update to my original posting, I purchased a LNIB set of Burris Signature rings # 420554 for Rimfire applications. These came with (3) pairs of clamping pads to allow one to use on 3/8", 11mm and 12mm??? They are not stamped so you have to mic them. I had a set of loose Posa blocks I assumed were same width as factory H&R barrel blocks to trial fit the rings on. I tried the Burris rings with all clamps included and felt the fit was just not there with any of them, too much daylight showing around base. I basically threw in the towel so to speak and removed the original H&R blocks from rifle to Mic and have new blocks machined to accept the Burris rings. While Mic'ing the blocks I notice they were .008 narrower than the Posa's......Hmmm, I grabbed the (3) different pads for a trial fit and Voila! a set allowed the rings to fit very well, I give it a 99% fit. I've seen dedicated rings/receiver which don't fit half as well. So now I feel I'm on to something and will do a trial fit of the scope asap.



BRKHornet



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