There were 2000 of the 6 1/2", 657 Classic Hunter produced. The run started with square butt revovlers, however by the time it was
completed S&W had transitioned to round butt. So you will see both version with the same product code. I put wood grips on both of
mine.
Shortly after that a run of 500, 6 1/2", 657 Classic Hunter IIs was produced. This was basicly the same forearm with the addition of a
single expansion chamber compensator that S&W likes to call the Power Port.
Eventually S&W added a 7 1/2" model 657 Classic Hunter to the catalog. MANY of these were produced over the years.