I found a Auction listing dated Aug 2012 for a Ruger 77ST
in .257 Roberts with 24 inch barrel and Ruger factory sights. The serial number listed was 70-59356. The 77ST 7X57 models were manufactured in the same time frame.
Ruger also cataloged a 77ST model in 7X57 with the 22 inch
barrel with out sights.
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