Could industry make new Iowa-class 16-inch guns?

Could the United States manufacture new 16-inch guns for reactivated Iowa-class battleships?

Eventually perhaps, but not quickly: restarting the lost specialist infrastructure and skills would be a major programme, so existing barrels are the practical option.

The answer considers ingots and tube production possible in principle but identifies rifling, lining, machinery, workforce training, and shell manufacture as the hard parts. Drawings and production instructions cannot replace the tacit knowledge of workers who learned how to make acceptable barrels through repeated experience. Rebuilt facilities would probably produce a poor first batch while the new workforce rediscovered those techniques. Ammunition production would also have to restart, although related work on re-entry vehicles preserved some useful knowledge about large high-performance projectiles. Refurbishing existing spares, extending barrel life, and improving propellants is therefore more plausible than recreating the entire industrial ecosystem quickly from scratch.