Yeah, S&W can tell you for sure. A while back I called about the ability of the 37 to take +p and the rep said if it had a -2 or -3 on the inside of the frame under the crane it is so rated. I just can't remember which it was. Also, I had a question about the gun handling the old Winchester Treasury load. They said NO WAY! The little J frames are only rated for about 21,000CUP and those 110gr were dishing out 23,500.