The theory about the canonballs was debunked years ago, all balls I'm afraid. "# The purported method of storage of cannonballs ("round shot") is simply false. Shot was not stored on deck continuously on the off-chance that the ship might go into battle. Indeed, decks were kept as clear as possible. Furthermore, such a method of storage would result in shot rolling loose and rolling around on deck, causing a hazard, in high seas. Shot was stored on the gun or spar decks, in shot racks — longitudinal wooden planks with holes bored into them, known as shot garlands in the Royal Navy, into which round shot were inserted for ready use by the gun crew. # Shot was not left exposed to the elements, where it could rust. Such rust could lead to the ball not flying true. Indeed, gunners would attempt to remove as many imperfections as possible from the surfaces of balls. # The physics simply does not hold water. All of the balls would contract equally, and the contraction of both balls and plate over the range of temperatures involved would not be particularly large. The effect claimed possibly could be reproduced under laboratory conditions with objects engineered to a high precision for this purpose, but it is unlikely it would ever have occurred in real life aboard a warship."