Hmm I was thinking of the barrel being a bell and pressure being how hard you strike it..
But the gas ball makes more sense...
After all a sonic boom is the air collapsing around where the plane was.
Right?
Many shooters think the big flash is due to powder that's still burning. But all the powder that was going to burn, did so long before the bullet exits.
Interesting. So it is an oxygen limited exothermic reaction?
I should go back and read the quickload documentation for % charge consumed....