That sounds correct to me Ken.
If my memory of history is right,
during WW1, shooting down observation
balloons wasn't easy even after incendiary
ammunition was introduced.
Also, Those balloons were filled with hydrogen
not inert helium like ,I will assume, the
recent version was.
I know that the Zeppelins that bombed
London were shot at and hit several times
without any effect.
BTW Yanks! Let the Canadians have some
fun too! Move over and let others play!
Cheers! - K