Why does gunpowder explode?

[Nate1778]

Why does gunpowder explode?

Wrong weight, wrong bullet, or something in the barrel.....

 

[MikeS.]

Thanks for all the info guys.

 

[hc1]

Modern powder, the burn rate increases as pressure increases, pressure increases as burn rate increases. On a burn rate and pressure graph chart it would show an increase to be exponential.
With black powder as the pressure increases the burn rate stays the same, so a graph chart of black powder burn rate and pressure would be linear
I belive this to be true...........if not someone correct me.