This firearm was introduced in 1909 & discontinued in 1936. (12A) is 22 S, L, LR with a 22" round barrel, using a single magazine band & had a straight grip on the buttstock.
Sorry I haven't been able to track down the exact date as of yet but still trying.
Depends on the model.
Remington Works - 1914 (late)
your Remington model 6 was made in 1998,due to the S prefix on the serial#.
1914
1913
1920
1919
1920
1915
1912
1920
1912