Around 1967.
what is the manufacturing date fo a colt diamondback serial number O72239
Diamondback serial # D69679. was mfg'd in 1975. made about 1976
I found a Colt diamondback with that serial number made in 1971.
1977
On the butt
made about 1977
Around 1968.
The Colt Diamondback with the serial number S79900 was manufactured in 1977. The Diamondback revolver was produced from 1966 until 1988, and the serial number can help pinpoint its production year. If you have more specific questions about the firearm or its features, feel free to ask!
are you sure the '0' is not a 'D' ????? in the serial number
1970
Post 1978. You will have to call Colt to narrow it down further.
Try looking it up at Proofhouse.com.