Some of the No. 5 carbines were finished with black paint (by the arsenal) as well as some of the Enfield .38 S&W revolvers.  Reason being that jungle conditions and humidity in a tank where the revolvers were used) would promote less rust if the finish was paint. 
The P13 (.256 Cal), P14 (.303 Cal) and P17 or "American Enfield" (.30'06 Cal) were all the same gun, British designed but built in the U.S.A.  Sgt. York used the P17.  My comparison was between the No. 1, k 3, No. 4 Mk1 and the Krag.  Just look at the metal finish of each and you can tell which would be the better made rifle  The Brits are fine military guns, but the Krag is a piece of Art.