If you will have a tapered model 15 (Combat Masterpiece) barrel put on a model 14 (K-38 Masterpiece) frame, it will fit but the forward upper frame contour will not match up.
A K-38/model 14 6” barrel . Should be easy to find another and have it installed, unless you need a 4”; in this case a later model 15 (-5 and later) version will match up.
Great info - thanks. That is what I was looking for.
The gun really has no collector value as the previous owner scribed an operation I.D. number on the side of the frame. I am more interested in getting 4" .38 for competition shooting. Already have a nice 14-3 set-up with a bomar rib for a PPC gun.