While I do not like the way S&W transferred blued K frame .38 Special model numbers there was some logic involved. Traditionally Model 15s had skinny barrels and Model 14s had what were for the time heavy barrels. S&W discontinued the traditional skinny Combat Masterpiece barrels, kept the heavy barrels and added even heavier full lug barrels. Since what had been Model 14s became the lighter of the two offerings their number changed to 15 and 14 went on the full lug .38s so it would remain the number for the heaviest offering.

Locally the most competitive 6" revolver for firing .38s in matches that only allow loading 6 cartridges is a 6 shot full lug Model 686 L frame with its cylinder milled to accept full moon clips. I do not think the full lug Model 14 would have any advantage over a 686.