Back in the early 1990's, the S&W Performance Center produced a number of Model 3566 pistols that were chambered for the .356 TSW cartridge which is based on the 9x21 case. The .356 case is 21.5mm long, but like the 9x21 it has a loaded OAL of 1.169 so that they can fit in a 9mm Luger magazine.
I have one of the double action 3566 pistols and I have found that I can shoot Fiocchi 9x21 123gr FMJ in it without any problems.
To answer the original question, I've never heard of a Speedmaster or any other S&W auto pistol chambered for the 9x21 cartridge.
After I stated that I had never heard of any S&W auto chambered for the 9x21, I remembered reading that back in the 90's, S&W did chamber the 5906 for the 9x21 for export to Italy. About 2000 pieces were so chambered. Never say never......