[OrvalWintermute]

Depending on the mode of shooting blanks, there is still a significant amount of pressure generated due to the gunpowder in the round. Therefore, anything in the barrel, including a weak blank-firing adaptor (which Hollywood appears not to use) could be ejected at a high velocity. This could eject through the blank firing adaptor also, breaking it off and turning it likewise into a projectile.

Military rifles fitted with blank adaptors are known unsafe at close distances.