I have an opportunity to metal detect a field about half a mile from a war of 1812 battle ground, and hoping to find a ball or two..
IF you can find a record of the diagram of the battle position, you will do well to find where the artillery was pointed..., and if there were small pieces used by the combatants. You may also have luck if there is a treeline marked opposite where a gun position was located. While people are squishy and don't slow down the iron, a ball fired direct, that is high and hits hardwood might then drop close and shallow after passing through trees.
The really small cannon that likely were purposely skipping a shot, alas would've been very mobile. These often maneuvered close to the infantry and had no set "battery" position during an engagement. So in that case if you can find where the opposing line of infantry was, and then calculate a rather oblique firing angle at that line..., you may find some skipped shot.
In the illustration below a good angle vs. open infantry in two ranks (War of 1812 formation) won't disrupt more than a couple privates in the line, BUT with an extreme angle, you can mess with the whole group, so, if you can find where the line was, and figure such an angle, then you up your odds at finding where the skipped shot came to rest. Good luck!
LD