Subtract the first 2 numbers of the serial # from 2000 and that would be the year the gun was manufactured
your glenfield was made in 1968.
Your serial number indicates that your Glenfield model 60 was made in the year 1974.
1975.
1975.
1971
1970
With the serial number that you have provided,your Glenfield model 30A was made in the year 1977.
1976
1968
1980.
Your serial number indicates that your Glenfield model 20 bolt action was made in the year 1980.
Double check your serial number. sales@countrygunsmith.net