Now I can't find where I read the Stevens SXS ser. # thing. I know it said Stevens used only numbers from the beginning till 1912, 1913 thru 1939 they used a capital letter with 5 numbers. 1940 thru 1968 the SXS's had no ser. #. In 1968 the U.S. govt mandated the gun mfg. to put ser #'s on all new guns. If I understood it right, Stevens started using a capital letter and a 6 digit number. started with A000,001 thru A999.999, then changed to B000,001 thru B999,999, then C000,001 etc. Only thing I can verify is my Stevens 311 with a date code of 1962 has no ser. # anywhere.