I'm thinking about having my Polytech M14S Duracoated(matt black) to include bolt, flash suppressor, sight parts, etc. How well can I expect it to hold up long term? Any problems with tight tolerance parts like the sights? I was also told AR bolts and carriers can be coated. How do they stand up to the heat? Exactly what is this stuff? What about lubing once the parts have been coated? Thanks.

Here at GunCoat Northwest we use Duracoat and have been very happy with it.  We LIFETIME all our work as long as your not using it in Law Enforcement/ Military.  Those guys seem to really thrash their guns and we can't cover people chucking their AR across a gravel pit.  
Duracoat goes on very thin, and is unique in the sense that it is flexible.  It's a 2-part epoxy base which helps the paint give a little should you bang it into something.  Other coatings are hard, which can be bad because if chipped, large chunks of paint come off.  As far as Durability, it has passed all mil-spec requirements including a 300 hour salt spray test.  This product is used by the Coast Guard, which obviously deals with inclement weather.  We have tested the product in the field duck hunting, as well as practical rifle competitions were I am slamming mags in and out of the receiver.  I won't deny that they get some wear, but it's the same wear all mags get after being used.  For more information on Duracoat check out our website, which has links to Lauer and other firearms related pages.  Feel free to call us with any questions(# on website).
-Andy
GunCoat Northwest
www.guncoat.com <-----New pictures updated weekly
[email protected]

i wouldnt put anything on the bolt and carrier.  if you let duracoat cure properly it will be durable as hell.  most people get anxious and mess with it too soon.  ive had mine done for almost three years.  one spot where it got wacked hard with something, even the rails have help up well.

I COuldnt find the pics I took. But my Camo AR has been duracoated goin on 4-5 years now. I use it for Tactical/Action rifle competitions. It has about 6k rounds thru it , give or take. THe finish is holding up well. The only areas that are showing signs are the Brass deflector & the Hogue grip (its rubber and flexes so some paint is wearing off). Ive got an ACE stock and even the foam is holding the paint well.no flaking etc. I had my paint job done by someone else and I know they used duracoated and baked the parts for short time.