You got some of it right
Rust and wet conditions with no ability to clean for days = plating
....
My long range p-dog rifles are not plated
Understood. Based on what little I know about barrels, mostly learned from Harry McGowan, plating and stainless or exotic metals do little for accuracy,
A very fine rifling job creates a smooth and consistent interior finish. Internal forces in the steel also affect performance. Harry, mostly retired now, did button rifling. He told me that my mountain rifle with his pencil barrel would shoot to point of aim repeatedly just as well as any heavy barrel. (You couldn't prove it by me, but that's what he said.) Good steel seems to work best and there are stories about Civil War sharpshooting rifles that were amazingly accurate at distance by the standards of any era.
AR barrels serve different needs and I would not expect such quality from a short, mass-produced barrel. I expect that chrome-plated AR barrels do just fine for their role.
