Hi, Colt38! I think you've got the, "apples and oranges," thing bugging you! The Diamondback is a deluxe Police Positive Special, which was a police duty gun from pre-war days. The D's got good sights and is very, "pretty." The rib and under-barrel weight do aid in accuracy, I think. I like the stocks, too. (John Wayne carries one in, "Brannigan!") dafariswheel, on these pages, has told us the D was an, "in-gun," with LAPD in their .38 days, too. The OMS is a target-shooters gun from an earlier era when lots of guys used .38 revolvers in NRA competition. It's a, "game gun." It was bought to make your groups tighter than the other guys! For this work, most guys wanted a 6" barrel and clear, adjustable sights and as light a single-action trigger as they could get. Sure, a cop could carry an OMS - lots of guys did! And, you could enter a contest then or tomorrow with a D gun and not cry over the results, I'm sure. (I'd pay $50 to spend an afternoon with both and see what the difference came to on paper!) I've shot both NRA bullseye style and police combat - a great deal, over the last 30 years or so and just love the shooting sports, especially pistols/revolvers. And, I needed one for work for some years. The evolution involved is simple enough - if we take it for what's happened and don't try to resurrect days-gone-by - which some of us like to do whenever we get the chance! (I really enjoy beating Glock scores with my Official Police!) The picture gets cloudy with so many guns that cross-over the lines. The S&W K-.38 comes to mind or the Python ... nice for target shooting and quite acceptable for police duty, too. Or the S&W #15, the Colt Diamondback, the new Rugers ... there's LOTS of guns that can go either way. So, ... which one do you WANT!? Makes me think of the old joke ... "How do you get to Carnegie Hall?" "Practice, son, practice!" Which is something else young people DON'T DO! But that's another story ... Happy Bullseyes!