[doctorj77]

I have a 1971 Trooper MKIII. And just noticed that under the top-strap, its marked either F3-10942 or F3-J0942. Almost looks like it was hand laser etched. Aside from a letter, does anyone have any clue what it could represent?

 

[spacecoast1]

Maybe a police evidence number?

 

[MtnSpur]

Inventory or armory number? Very hard to nail down random numbers without provenance of who owned or where it shipped. Evidence number would be as good a guess as the other.

 

[03clyde]

Maybe a police evidence number?

Very probable.

 

[elric]

It was probably a police evidence number, or maybe an asset/weapon tracking number, for a police agency or armored car/security guard company.

99.99% chance that Colt didn't do that, so a letter wouldn't help, except to maybe show you it was shipped to police or a guard company who may have put that # on it.

 

[dfariswheel]

It was written with an electric pencil.
You sometimes see this done by an owner as identification if a gun is stolen.
They put the number on guns, TV's, and electronics.
Some police departments used to loan the electric pencils, and I seem to recall there was or is a national data base of who each number was used by.

On the bright side, at least they didn't put it on the outside of the frame.