I have a 3inch 547 myself, and it's one of my favorites. I read about it at first in gun magazines in the early eighties, but it's only twenty years later I managed to get one for the equivalent of about 200$. This particular gun must have had a very interesting story, as it came from a police officer's widow, who sold it to my gun shop, who only saw it as a difficult to sell variant of the M&P series, which was my fortune of course. I personally think it has been a kind of test gun, probably with the hope to interest the Belgian Police for the project too, but I have no evidence at all for that, except for its outstanding manufactory.
I had it lettered by Roy Jinks, and it seemed to be one of the early pilot runs (one of the first 152 build between 1979 and 1981). It has one of the very best actions I have ever laid my hands on, and it still has the pinned barrel, a feature dropped later in the full production run. I load very mild 9mm ammo for it, FMJ 123gr, and with that load it's incredibly accurate, even at ranges between 10 and 25 yards. The original grips have been lost through time sadly. It came with Pachmayrs, which I changed to Ahrends, and it's a gun only to be described with superlatives. Never had one single failure what so ever, including extraction.
In very short, its story is as follows. Around 1977, the French Police asked S&W to develop a 9mm revolver with the intent to renew their range of .32 pistols with something more powerful. A specific request was it would not use clips, but the gun should operate as classical revolvers for chambering and extracting cartridges. S&W started developing the gun, and the very first one was produced in 1978, as experimental model 47. The original intent was to produce 4inch guns only. Some first pilot runs were made in 1980 and 1981 (the other 151 as mentioned before) and were then officially named model 547, of which only a minority had 3inch barrels. It's only in 1983 when full production started, to be dropped of the catalogues in 1984 for lack of bad sales, as in the meantime the French Police adopted a French product, the Manurhin revolver (which is also a very high quality product I must admit, but I prefer S&W), and which has now been dropped for semi-auto's. Total production according Roy Jinks is 10,270 units, of which a majority seems to have 3inch barrels (about roughly 2/3).
My advice out of my own experience is to grab it when you see one, and hold to it. It's a gun with a story, and a great shooter too. Each time it comes with me to the range, after the very first shots, I have that silly grin of my face of pure admiration and satisfaction. It's a true S&W in the best tradition, the ultimate M&P ?
Question : are your 547 also scaringly precise, or is this just further good luck I had ?