Post the serial number and we can tell you when it was born.
It definitely wasn't in 2010, as it doesn't have a lock. (That's a good thing).
I bought one new when they were first introduced in about 1996. Carried it constantly. I only stopped carrying it when I got a M340PD a few years ago. The M640-1 is a great carry revolver. Yeah, it kicks a bit with full power Magnum loads since it weighs about 23 oz. In comparison to the 12 oz. M340PD, it is a delight though.
That said, both of them were always stoked with Federal 125 grain magnums. I just didn't shoot hundreds of them in an afternoon.
Jim