The Pivot gun you show on US Hamilton, works very much like a Mortar excepting for the lack of elevation which necessitated the deck strengthening for the latter. I would think that as a medium sort of gun firing on a slide similar to a Carronade it could dole out about the same damage as a chase gun. Quite deadly at close range to any more flimsily built vessel. Just watch out for your own masts and rigging.
Rob.