I have a 5906TSW, 4003TSW, and CHP 4006TSW. I like them all, but for several years I have been on the lookout for a 5903TSW in excellent condition for a reasonable price, with no luck.

Reading some other posts on here about 357 sig conversions and a lightbulb went off about exchanging slides and frames. I just tried fitting and the complete upper 5906TSW slide seems to fit and function perfectly on either 40 cal frame. Any reason I shouldn't try my 5906TSW slide on the 4003TSW frame at the range? It would be my favorite combination of capacity vs weight. Thanks.