Did a little online searching this morning and came across this article from Gunblast http://www.gunblast.com/Cumpston_K22s.htm where the author, Mike Cumpston said, "Post World War II, the factory promised that each K Series target revolver would group five rounds inside of 1.5” at 50 yards."

In looking at other forums, very few owners give much more info than, "It shoots better than me" and, "It's very accurate". Of the very few posters that did give some actual numbers, it seems like 1.5" at 50 yards is about right.