When was my gun made?

[642Fan]

I just got a beat up old model 10-7, 4" with serial number prefix 5D. I've struggled through the internet and found that 5D were made between 77 - 80.

How do I narrow down the manufactured year? how many more digits do I need to date the gun?

Sorry if this is a dumb question. Thanks.

 

[haywood]

I say 1979

 

[642Fan]

Thanks. That works.

 

[haywood]

Thanks. That works.

I don’t know why it went sideways and then flipped upside down or whatever happened but at least you got the picture