The fancy new light for my borescope showed up, so I started looking at barrels. Obviously, the borescope doesn't tell you dimensional accuracy, but it will show you gross issues - roughness, uneven appearance, other defects.
The best looking barrel on the inside was actually the Shilen/Rainier AR-10 barrel. The bull barreled 5.56 Armalite, which is currently in 2nd place, looks almost as good.
An AR-10 bull barrel that has proven so-so in the past has reamer marks in it; I have another one that looks better, so I think I'll swap them and try it this weekend.
One that was really interesting was the Daniel Mk12, which had disappointed me - It looks pretty good on the inside, but the muzzle has no chamfer at all. Nada. I'm thinking before I buy another barrel, I'm going to chamfer the muzzle and see if that helps.
