But what if you have sealed the flash hole and pan with tallow, just like Gary Paulsen's hero Patriot sniper in his novelette "The Rifle"? In that novelette, the rifle was still in perfect condition even after 200 years, and a single spark finding it's way into the flashpan ignited a sequence of events which is a stark reminder of the importance of firearms safety.
If the chamber would be fine, the powder charge still viable, and the pan sealed, I think that particular British general, and perhaps some of his vicious attack dogs, the "Black-and-Tans", would be learning a lesson about just how dedicated the Irish will fight for their freedom, particularly if our hero has also stuffed his rucksack with a pack of buck and ball cartridges and plenty of powder.