Danish Rifled 18-Pounder at the Danish War Museum

Many thanks to Rob from the YouTube Channel FirearmsAddict for sharing these photos!

A Rifled 18-Pounder is displayed at the Danish War Museum in Copenhagen. The photos show a cast-iron tube manufactured in 1837 that has a reinforcing band (likely wrought iron or steel). I expect this gun was originally manufactured as a traditional 18-Pounder smoothbore. I also guess that the rifling and banding happened circa 1860.