Shortbow, and Dave. The difference is that when a frying pan is seasoned, its heated in an oven to 500 degrees. When a blacksmith douses a completed work in oil to give it a black finish, the item is often near its melting temperature, but is almost certainly heated to more than 500 degrees. When does anyone heat a barrel to 500 degrees before " Seasoning" it????
I make my own vent picks, using a propane torch to heat soft coat hanger "steel " hot enough to forge on a small anvil. When I have them finally shaped I heat them up and spray them cool with WD40. If I have some oil open around, I have poured that in a small dish, and just dropped the picks in the oil. Same thing you are talking about when blackening knives, axes, or other parts.
Part of what you get is SCALE. There is NOthing consistent in the thickness of scale. I measured my first Bowie Knife with a micrometer, after it came out of my first heat treating effort covered in scale. The numbers were all over the place. As slick as my picks come out, I would never consider the coatings to be uniform on them, nor consider doing the same thing to the inside of a barrel.
So, I politely disagree with both of you about seasoning a steel barrel. Long years of experimenting with every way to get more accuracy out of barrels indicates that they work best when they are clean, to the bare metal. Polish them, to the point of using a lap in the barrel between matches, but crudding up the barrel is no way to get it to shoot.
I did experiment with both Black Chrome and normal ' white " chrome plating the bore. No question it fills the pores of the steel, and makes the barrel easier to clean. But Homer Dangler, a long time famous gun maker, did some before and after testng, and he found no improvement in accuracy with the chromed rifled barrel. When I talked to the plater, he was not surprised. He told me that while the plating is measure in 10 thousandths of an inch, there is no way to guarantee that the same amount of chrome is layered on all parts of the barrel.
Chrome is too brittle to polish, or lap, or burnish, so there are limits to what you can do with it. Chrome plating seems to make the most sense to use in cartridge chambers, and in shotgun barrels, where keeping crud out of the surfaces is paramount to the best performance. This is particularly true with Semi-auto firearms.