Reply #25: No; it's the combination of firearm, propellant and projectile

[Euromutt]

Nobody's ever been killed solely by the propellant in a blank round. The problem is that some blanks use a wad to keep the propellant in, which is then ejected with sufficient force to inflict trauma. In the (in)famous case of Brandon Lee, the blank expelled a bullet which had been lodged in the barrel after being fired from an improperly prepared dummy round (the crew had removed the propellant from the cartridges, but not the primers, creating "squib loads").

At the same time, a cartridge that "cooks off" in a fire cannot, in the absence of a firearm's breech, chamber and barrel, generally focus the expanding force of the propellant sufficiently to impart lethal velocity to the bullet. Available evidence strongly suggests that the bullets will fail to penetrate protective clothing like firefighters' coats.

In short, you need a full round of ammunition (the propellant won't combust without a primer) discharged in a firearm.