for educational purposes: SAAMI firefighter training video

what happens to ammunition when its ignited outside of a firearm

at the moment the .500 S&W magnum is the most powerful handgun cartridge comercially available*

*tell me if i'm wrong. i'm not here to start a fight

when dropped from 65 feet

when shot with another gun

when blown up with a blasting cap

driven over with a bulldozer

18000 rounds set on fire

250,000 rounds of ammunition ignited inside a semi trailer

https://www.youtube.com/watch?v=3SlOXowwC4c

The Sporting Arms and Ammunition Manufacturers' Institute (SAAMI, pronounced "Sammy") is an association of American firearms and ammunition manufacturers. SAAMI publishes various industry standards related to the field, including fire code, ammunition and chamber specifications, and acceptable chamber pressure.

http://www.saami.org/

yes, the rounds do explode while on fire. the purpose is to show that they're a very low projectile risk to firefighters.
that said if there is a loaded gun in a fire it will eventually shoot as if someone pulled the trigger

boolits