Here is a story that i was told-not sure of the M13 being available in Nam years tho so forgive me if this is inaccurate regarding mdl of the Smith:
I had some gun dealing a few years back with man who was nam vet and we got on that for a bit on the phone. He was point man and I forget the unit now , but carried a M12 ( Winch shotgun ) and used it to kill a NVA or VC officer who he said had a M13. As a war souvenier he declared it and returned with it. he researched the gun via serial # and discovered it had been issued to a pilot of an aircraft i forget now, but he was shot down and killed. Assumption then is that the 13 was captured by the enemy and then recaptured by this point man.
Anyway, the point man I was visiting with tracked down the family of the pilot to return the 13 to them, but they rejected it, I suppose due to resentment of the loss of their loved one. Thus, he still had it some 20 years ago.
No extra charge for non S&W stories.
I never saw a M12 used in the '69-70 tour I did but we had a well used 870 and even some all brass shells for it. Our CO carried it one op and had an accidental discharge with it and of course it was the gun's fault so it disappeared from our company (9th div C co/5/60th)
Also met man at VA who was infantry and i asked about souveniers-he had a Browning HP he captured when officer in spider hole in Cu chi area shot this GI's helmet off from below, grazing the GIs face and ear.
Infantry survivors count your blessings!!!
We also captured a chi com tokarev that my friend shot holes in while finishing the Charlie off by moonlight.