Re: What exactly is MARINECOAT?
If Mossberg were to build an all 416 stainless steel 500/590 (minus the furniture), and finish it in black phosphate like Olympic Arms uses to make their SS match barrels black, that would be about the most corrosion resistant shotgun ever made (no aftermarket finish required).
Yes, it would be heavier, but all the better to help manage recoil.
It would also cost more, mostly due to raw materials and tooling, but if they kept it at or slightly under $500, I would be one of the first in line to buy one.
If you can find out what the marinecoat finish is, I'm sure there are many here who would like to find out.
If it is Robar NP3, I know a guy on another forum who's had a couple of his submachineguns done in it. And he loves them.
Cleans easy, minimal lubing, etc.