Sorry, Bf109 fans, but the K-4 is pure easy mode. The gun is slightly hard to hit with, other than that it is pure cake. It dominates the P-51D so badly at anything other than mud moving and endurance that you ought to be ashamed of yourselves for claiming anything else.
I know it is nice to talk up your skill level and make it as though you're one of the elite players of AH because you use Bf109s, but that is pure fiction if your Bf109 mount is a K-4.