DOM of Colt

[dr.magnum]

I've got a pre-war Colt Official Police,38spl. It was a state trooper sidearm. Can you tell mewhen it was made? The serial number is 56173x. There is a light D under the serial number on the frame, and there looks like ther is a T in front of the number that is high and to the left. These are only on the frame. The same number is on the crane, but nothing else. Thanks.

[XavierBreath]

Try this reference site.
http://proofhouse.com/index.htm

[dr.magnum]

Thank you. I found it. It says it was made in 1930. Right at the start of the Great Depression.