I have several .357 SS NMBHs that my wife and I use for CAS. When I got a pair of 50th Anniversary Blackhawks for my wife, I had a spare pair of 4 5/8 .357s. I sent one in to Ruger for a 6 ½ barrel and a 9mm cylinder. The down side was they kept the hammer and trigger I had smoothed to provide a terrific trigger. On the good side, I got a very accurate gun back that shoots very nice groups in .357 and is nearly as good, despite the difference in bullet diameter, with CCI Blazer in 9mm. I wasnt surprised by the accuracy in .357, but I was surprised by the very good accuracy with the 9mm Blazer. I havent used enough other ammo to know yet if it shoots other stuff as well.