Proofhouse.com has Colt sn data.
@1914
made in 1972
about 1920
@ 1972
Rifle or pistol?
The caliber should be marked on the slide.
Impossible to answer without knowing who made it.
A Colt 1908 hammerless .25 with that serial number was made in 1912
The caliber of this weapon is .45 ACP, or it's full name is .45 Automatic Colt Pistol.
0-1000 uSD
@94 yrs old
100-800 USD