This is a .300 H&H Magnum standard barrel, manufactured sometime between the years 1959 and 1963.
Bluing - 95% - This barrel shows minor signs of wear. The bluing has faded in a couple small spots throughout the barrel.
Metal - Overall, this barrel is in very good condition. There are some very minor nicks near the base of the barrel, but no notable scratches or other forms of metal damage.
Bore - 6/10 - The bore shows some signs of wear. The rifling is bright and smooth throughout the length of the barrel, but there are several spots of light pitting in various points throughout the bore. Borescope verified.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE