As yet another illustration of how we should never again be surprised by the Internet, even if we inevitably are: bronzecannon.com
(They're bad people: they loot shipwrecks, or pay people to do it for them.)
It is strongly recommended that these antique cannons are never fired, as it may cause damage to the cannon, to yourself and/or to anyone in close proximity. We assume NO RESPONSIBILITY of any kind for any attempt to fire these antique cannons!