This is a variation of the K-frame Military and Police revolver originally produced for the U.S. Air Force. The original version had an aluminum frame and cylinder. Unfortunately these things did not last long, even with reduced power ammunition produced specially for them. They were then manufactured with a steel cylinder, which helped. Many of these weapons were destroyed for the Air Force.
The reason I am writing this up is I came across one at a reasonable price a few days ago. I didn’t buy it, as I shoot the guns I own and shooting this one would just tear it up. I did, however, consider it.
These weapons were produced in five variations. All of them but the final one, the 12-4, had a narrower than standard frame. They were in production from the early 1950s through 1984. They were produced in a 2″ and a 4″ version. In a 2″ variation they weighed 18 ounces with the steel cylinder.