what is the manufacture dateof springfield serial# 1226813
it was produced in 1931.
With the serial number that you provided,your Springfield model M-1 Garand rifle was produced in the year 1942.
http://oldguns.net/sn_php/mildateslookup.php The gun was made in 1903
your springfield model 1903 was made in 1919.
Somewhere between 1948 and 1962.
made by Colt for US Navy. not unusual to see a springfield slide on a Colt frame
If your Rifle was made by Springfield then the production year was 1910.If your rifle was made by Rock Island then the production year was 1920.