The earliest guns were breech loaders, made from bar iron banded and hammer welded into a tube. A separate breech chamber held the powder charge. Gun founding became an art with the introduction of one-piece sand cast tube.
The lower tier of 17th-century English ships of the line were usually equipped with demi-cannon, guns that fired a 32-pound (15 kg) solid shot, and could weigh up to 3,400 pounds (1,500 kg). Demi-cannon were capable of firing these heavy metal balls with such force, that they could penetrate more than a meter of solid oak, from a distance of 90 m (300 ft), and could demast even the largest ships at close range.