After January 1, 1907 1903 rifles not made from already made misc.dated parts, the bbl date and serial numbers indicate the approx. date the rifle came off the assembly line.
Serial Number Barrel Date
63499 4-07
65975 3-07
71587 4-07
87229 6-07
94160 8-07
10607 11-07 Added 12-29-19