This is a factory sporter barrel with original finish. It was manufactured between the years 1955 and 1957, based on the #6 sight ramp with 14 lines.
Bluing - 90% with light freckling in the roll stamp area. It may be possible to polish this out or improve it with bronze wool. This barrel would also be an excellent candidate for rebluing.
Metal - Excellent with no damage or visible pitting associated with the bluing freckling.
Bore - 7/10 borescope verified with some light wear, but plenty of life remaining.