I would not fire .357 in a gun that light anyway. It hurts. The cylinder might handle it, the frame might not. I don't know for sure. Why take a chance on ruining a nice gun?

Also, it will swell the brass near the base. The 9mm base is a few thousandths larger. This may not be a concern if you don't reload, but the brass would be toast, in my opinion.

I agree, TK Custom is one of the greats.