The "G" is probably a revision number, changes made to a design were designated by letters and stamped into the action near the serial number.
Winchester started using the G prefix to the serial number in January 1969.
Please indicate what model number of Winchester goes with that serial number,so I may answer your question.
Please check your serial number! Winchester did not start the G prefix until serial number 941,000 on the Winchester model 70.
1918
1920
The G makes the number come up as invalid. Without the G, it comes back with a manufacture date of 1971
@1941
The G prefix to your serial number shows that it is a model 70 Winchester rifle.It should say this on the barrel of your rifle.
g8
1971. They began adding the G prefix in 1968.
I have to admit I am a little confused by your serial number.My records indicate that the winchester model 70 did not have the G prefix until after 1968,but your serial number provided by you indicates that your winchester model 70 rifle was made in 1966.
G. A. Winchester-Gould has written: 'The guide to Botswana' -- subject(s): Guidebooks