I believe that there were 2 batches of M-686 Mountain Guns made about a decade apart. The first was the 686-5, made in about 1998. 7 shots, Hogue rubber stocks with moulded-in S&W medallions, no internal lock.

The second batch was announced last year, 6 shot, internal lock. These were made up for a particular distributor.

I bought mine new in October, 1998. I like it a lot. Great holster gun.