S&W K14

[ser2711]

What is the difference between K14-3 and K14-4.?

 

[SmithNut]

Assuming you are referencing the Model 14-3 and the Model 14-4, according to the SCSW V4, the -4 engineering change covers the change to the locatioin of the gas ring, moving it from the yoke to the cylinder.

From a nomenclature, the original gun was (and still is) the K38 Masterpiece, when model numbers came along in 1957ish, this fine old gun also became known as the Model 14 (and several iterations down the road).

 

[Lobster Picnic]

The pinned barrel was dropped during the 14-4 run also. The later ones won't have it.