I've Dura-Coated a number of guns with great success.
Baking the finish does make it more durable but the truth is it is all in the prep.
Dura-Coat offers a self contained spay system that works very well.
I have used it a couple of times for small parts refinishing.
A HVLP trim gun or air brush from Harbor Freight works great and fairly cheap.
Here is a few pic's of a British Lee Enfield I did a while back with Dura-Coat.
This is my range 303 and see's a lot of use.
IMG_1023 A.JPG
IMG_1033 B.JPG
IMG_1037 C.JPG