I, uhm, did something similar once.
At the range a few 6 or 7 years ago, i was just getting in to front stuffers, shooting my Traditions .50 Pennsylvania flinter very slow and deliberately, explaining every step for the benefit of my buddies 9 year old son. Swabbed the bore after 5 or 6 shots and , apperently, didn't dry it out enough. Next shot, click! And so on. Figured after a while all the powder musta' stuck to the to the inside all the way down and dryballed it. It sat like that for 2 or 3 years while I tried every stupid trick I'd ever heard to unstuck the ball. Finally, someone tells me to unseat the barrel, elevate and heat the breach end, the patch will burn up and the ball will just roll out. Genius! So I take it out to my backyard, in the middle of Philadelphia, and after 5 or 10 minutes..... KERPOW! Good thing it was pointed at the ground or it would have been a very bad day.
Neighbors: what was that bang!?!
Me: I dunno, musta been some jerk with firecrackers.
(Slowly backs away)