Dan Wesson made 357s in different barrel lengths. I have a revolver with 2 1/2", 4". 6", 8", 10", 12", AND 15" barrel assemblies. The 2 1/2 through 8", were bought as a set. I bought the rest of the barrel assemblies after I bought the set. I am a Dam Wesson "nut" and have collected several of them. Some of them special, most just average used revolvers I picked up.
I am here to tell you I wish I had been younger when I got the 15". Now I have a shooting rest to shoot the 15" accurately. And yes, it is VERY accurate when I do what I am supposed to do!!!
Steve