[bacondude3]

Do you have a source for that? I don't really understand why shotgun rounds would be less dangerous, particularly if rifle rounds are more dangerous. More powder = more dangerous would make sense to me, but that doesn't sound like what you're saying.

Some parts of Florida are more humid than Appalachia, so maybe the difference between 75% and 95% humidity has a greater effect than 55% to 75%.

[Retric]

I was told the rifle rounds where more dangerous, but not why. My suspicion is the plastic tube around a shotgun shell loses strength before the round is hot enough to go off ~200C. Though it’s probably more complicated.

As to humidity, I don’t know it might be just extreme humidity or it could be humidity + temperature, or perhaps we had a bad case of ammo to start with.