I believed it was .357 because my knowledge of S&W revolvers as a whole is rather limited, and I had to don my 10x magnifiers and get it under a good light to read the 38 S&W Special. It has almost been rubbed off of the barrel which leads me to believe at some point this was an issue weapon for a P.D., and then my Grandfather bought it (where and when are lost to me) and he passed it on to my Dad who passed it on to me. It still locks up well, the timing seems to be fine, the hammer won't push off, and much to my delight, the trigger is like butter. It's smoother than anything else I own. Whoever owned it before my Grandfather obviously abused it, because neither he nor my Dad allowed rust on a gun. You got to go to bed after the firearms were cleaned and properly lubed and wiped down. It's a habit that has stayed with me.