UPDATE
Thanks to all who have responded. I have unearthed some great info, and now have in my temporary possession an undocumented but serialized Superior rifle (#31) in 222, with a HArt BBl. It is the very rifle pictured on cover Precision Shooting, Vol 29, No5, Sept 1983. I have about 100 of Shermans bullets, 53 Gr HP match. i intend to do a "Then and Now" comparison of bullets and optics on the rifle as soon as our weather clears. This should be a great "time capsule" endeavor, because though the bbl is a sporter, it is my hope that i can gain some appreciation of the action that won many BR events in the early 60's. I am hopeful that I can produce an article that would be accepted at PS.
Snert