Just got done shooting a Browning Challenger II a few weeks back, and it turned out tits (was home on holiday for a while and went on a spraying craze coating everything that wasn't nail down).
I blasted the metal, and then let the parts soak in acetone until I was ready to paint (to make sure it was degreased). Tricks is to wear de-powdered latex gloves when you paint/ degrease (read put them on and go wash you hands using water), and let the painted parts dry for 24 hours before handling (takes a few weeks for the urethane to get bullet proof, so don't expect the pistol to be holster ready until then). Also, if you are using a compressor/airbrush, make sure that you have a dehumidifier in line.
Also, a little urethane goes a long way. Since Durcoat has to be mixed, I turned a little tester’s paint bottle into one of my air brush supply bottles. It's small (read enough paint to shot an entire pistol), and clear to see for mixing portions needed. Plus the bottom of the bottle is canted, and if you angle the pick up tube/bottle correctly, you can draw every drop of paint out of the bottle.
I spray at 45 lbs with almost a light fogging pattern spray for a matt like texture (match anodizing), and 50 lbs with thicker pattern for a smoother glossy type finish. Before you shoot, take a minute to adjust the air brush feed and air pressure on a piece of paper to get the desired finish before shooting the parts (Dura allows a flat finish, were moly will be glossy once baked).
As for wear proof, don't worry about it. If you do manage to scrap the finish, buff out the scratches with acetone on cloth patch, and just re-coat the section. Trust me, Duracoat/Polaine will out wear gun bluing by months of holster wear (and touch up on takes a few minutes to repair).
Now the fun part, Duracoat flat has a flat finish when sprayed (works great for a matt finish), but say that you want a shinny gleaming gloss finish, this ones a walk in the park also (even using flat). Shoot the finish a little on the heavy side, and let it sit for a few days. Then use a cotton cleaning patch lightly soaked in acetone, and gently polish out the parts to get them to a gleaming glass like smooth.