Bill,
You underestimate my surprise. Although, thinking about it, this was at the height of the industrial revolution when most of the fundamental modern steel processes were developed.

That work the Zircon embarked on was to provide a looking glass back into the steel making of the early 20th century. I suspect he'll find pretty sophisticated alloys similar to modern stuff. Modern (contemporary) shotguns really haven't used much in the way of the very modern metals for the most part. I think purity is where there's been a lot of work, although we find very small inclusions at failure initiations in very expensive Vac-Arc alloys like 300M and HiTuff.