I was inferring that it would have to have some sort of propellant in order to be fired out of the barrel of the gun at bullet-like velocities, and you mention that it has some sort of object memory property that mimics the bullets in question. From there I inferred that it would either have to propel itself via some unknown method (in which case the gun wouldn't even be required), or it takes on the form and function of a full bullet casing including that of the gunpowder. If that was the case, what's stopping it from using its material memory from creating a knife or sword or other physical object?

All I'm asking is how the goop actually functions. Everything else in the CS is described in vivid detail, so I was hoping you'd put an equal amount of thought into how the supernatural aspect works as well.