I remember a few years back word going around the internet that Apple had released an iOS update that allowed the latest model of iPhone to be recharged in a microwave…
Ooh, ooh. 12ga shotgun shell (~18mm), cut down to remove the shot but leave the wadding, drop the 18650 in there musket-style, and blast it into a brick wall.
18650… that’s a little loose for a 12 gauge and a bit tight for a 16 gauge… but I bet it would fit nicely in a in a high-brass 3” 12g birdshot shot cup.
Just Saying……
Or, maybe you have a pair of large jaw vice grips or channel locks that need heat treated?
Or it’s possible the sidewalls of the battery will buckle due to the high acceleration involved, jamming the battery inside the barrel, likely damaging the barrel and potentially even creating a risk of overpressure.
I wouldn’t recommend it without taking significant precautions.