maker of the firearm and model first, then serial number

Flint lock

Bule Book of Gun Values

A shotgun is a firearm. A revolver is a firearm. A pistol is a firearm. A rifle is a firearm.

If you want even more specific -- A Remington 1187 is a firearm (shotgun). A Smith and Wesson 686 is a firearm (revolver). A Sig Sauer P226 is a firearm (pistol). A Colt 6920 is a firearm (rifle).

Depends on the firearm. You can contact me through my messge board, and if there is a public data base for THAT make and model, will try to direct you to it. Does not exist for all guns.