In WWI the UK developed AA rounds to shoot down zeppelins and balloons. They were basically tracer rounds with a bigger incendiary charge that ignited when fired and set the skin and hydrogen of balloons on fire.
Modern incendiary and explosive rounds fired by fighter jets aren't effective against them becayse they are only triggered by their impact against a hard target, but I'm sure the DoD could come up with a more effective version pretty quickly if it came down to that.
Modern incendiary and explosive rounds fired by fighter jets aren't effective against them becayse they are only triggered by their impact against a hard target, but I'm sure the DoD could come up with a more effective version pretty quickly if it came down to that.