Alec Baldwin fired the prop gun that killed cinematographer, injured director on "Rust" film set

[Straw Man]

70. Close, but not quite.

A dummy round is usually a cartridge containing a bullet, but from which both powder and primer have been removed. In a close-up of the front of the revolver, it needs to loaded with dummy rounds for the sake of realism because the tips of the bullets need to be visible. Dummies are also used when someone needs to be shown loading a gun.

You are correct that these dummies were prepared improperly, with the primers left in, but the force of the primer alone is usually not great enough to propel the bullet out of the barrel. Instead, it may propel the bullet into the barrel, where it can get lodged; that's what happened in this case.

The gun was subsequently loaded with blanks, cartridges that contain primer and powder but no bullet. When the blank was fired, it propelled the stuck bullet out of the barrel, killing Lee.

This should never have happened, and was the result of negligence, both in the creation of the faulty dummies and in the failure to make sure that the gun was clear before loading it with the blanks.

I don't really know what happened in Baldwin's case, but I suppose we will find out. One other point: I'm seeing a lot of references to a "prop gun." To the best of my knowledge, a prop gun is a non-firing replica. That doesn't appear to be the case here. This was a real gun. Also, the notion that blanks are completely safe is a dangerous one that needs to be dispelled. At very close range, they can be deadly; although there is no projectile, there is a tremendous amount of force coming out of the muzzle. That force dissipates quickly over distance, but if it is contained, such as by placing the muzzle against something solid, it can be devastating. This is how the actor Jan-Erik Hexum died; he essentially fractured his own skull by "simulating" suicide with a blank-firing gun.