I've just had a Beretta Ultima barrel done with Cerakote. The barrel finish was Beretta's usual standard, overpriced crap.
Any threat of rain, the barrel rusted. Don't even think about what it looked like after a morning on the fore-shore. So I visited my nearest approved Cerakote distributor.
The result looks very good, and I don't see any problems with any further weather related damage, BUT?
All the proof marks, chamber length information, 'Please read instruction manual' etc. Have disappeared. They have been completely filled in and smoothed over with the coating.
How do I stand if I ever want to sell it? As the proof marks are now illegible, is the gun out of proof?