There was a Ranger Arms Inc out of Gainesville TX that manufactured a bolt action rifle in various calibers in the early 1970s but I suspect yours is a Sears, Roebuck & Co. This was a house brand name for many Sears firearms sold. Their model number identification system is consistent with the way yours is numbered. I don't see a 103.1 in my listings but there are quite a few 103.1xx through 103.1xxxxx listings. I would suspect that yours was actually made by Marlin though as all the 103 series seems to have been manufactured by Marlin, most likely either a variation of the Marlin model 80 or 81.
