I've searched the archives and I can't seem to find a good answer to my question. Here it is.
My pre-ban lower (Bushmaster) is showing its age I would like to have refinished with the hardest (metallic?) finish I can find. I'm not to worried about color, as long as it's somewhere between gray and black. Right now I'm considering MetaCol III.
I don't know if it's "hard" or "soft" anodized. If anyone knows, please let me know.
BTW: how much harder is hard anodizing over soft anodizing?
Since it's a semi-auto you should find a place that will do mil-spec anodizing. That would be a Type III, Class II anodize sealed with nickel acetate unless I have my facts cornfused. You'll have a much easier time finding a place that does real anodizing. ARS (the metacol guys) allegedly can have anodizing done. Call them.
I prefer anodizing since it's mil-spec. I'm getting my M16 lower moly resin coated due to cost and convenience. It is not my first choice.
When the military is having parts resin coated it's going on over anodizing and phosphating which is ideal. That's the optimum finish for durability in my opinion.