Would need model name to answer.
Impossible to answer without a detailed description of all features and markings.
If your Colt Stagecoach was made from 1965 - 1968 it will not have a serial number.
your rifle was manufactured in 1894.
What is the age of a Colt rifle serial SLD25319
Proofhouse.com has Colt sn data
The Colt lighting .22 rifle with that serial number was made in 1899.
a gunsmith needs to check both the ammo and rifle.
1885
1894
1889
What is the manufacture date of a Colt AR15 rifle serial number 192754 model SP1
The Colt AR-15 rifle with Serial Number 100677 was manufactured in 1962. Colt's production of the AR-15 began in the early 1960s, and serial numbers from that period can be referenced to determine their manufacturing dates. For precise information, it’s best to consult Colt's official records or a reliable Colt AR-15 serial number database.