On the 700's they started going up the alphabet every 5 years starting in 1970 (or 80 - eek) I just don't remember HOWEVER all 700's are date code stamped ;)
On the left side of the barrel just before receiver with month/year. The details of this/table are on the Remington Society of America, I will add a related link with pointer to information.
1920
That is not a serial no of a Remington 1911A1 they stopped in 1945 with 2465139.
I checked www.oldguns.net and they show the manufacture date of Remington 1903A3 serial no. 3851292 as 1942.
RW isn't part of the serial no, it stands for Remington Works 1915
To determine the year of manufacture for your Remington 760 Gamemaster, you'll need to reference the serial number against Remington's production records. Remington began using a specific serial number system in 1921, and the first two digits often indicate the year of manufacture. For precise information, you can consult a Remington firearms reference guide or contact Remington directly with your serial number.
1912
1920
1924
1912
1912
1923
1914