I wished you had a picture, follow the advice and give S&W a call. Being a 38 special, but not mentioning a model name, like model 10, which it sounds like to me, it is probably older and a .38 hand ejector model. Regardless, I will tell you this, with 158 grn, lead round nose, it will probably cluster the shots, at point of aim, at least to 15 yrds, and don't be surprised at 25, OK, go ahead and be surprised.

I can't give a value, until We know what it is.