Welcome to the Forum! First of all, The Model 66 was a classic of the late '70's & '80's - purchased by many police agencies across the U.S. It was one of the last popular revolvers I saw in LE holsters before the adoption of the semi-auto pistol.

While S&W made commemorative models honoring various police agencies, usually including an agency emblem on the side plate or frame, individual "rack" numbers, like F731, would suggest the guns were issued for use by the department indicated. I, personally, enjoy owning and shooting guns that were used by LEO's and like to find/research a historical connection that may serve to better appreciate the design, manufacture and use in that context.

Now, we would really appreciate some photos & a range report. The Model 66 is not uncommon, and unless you have one that was once owned by someone special - you may certainly enjoy shooting it without diminishing it's value significantly. If you give us the serial number (use "x's" for the last 3 digits), and the Model number from the open crane of the gun, including the "dash" number (ie., Model 66-1, 66-2, etc.), we can help get you close to the year the gun was shipped from the factory.

Jerry