Even as an actor, if you are handed a replica of a deadly weapon you have a responsibility to make sure it is functioning properly and safe. And every actor should know that those firearms they get handed are most often real and can fire real ammunition. In such an environment, (particularly if you are also a producer - aka management), YOU are the final safety step before the director yells Action!
The “I didn’t know it was loaded” is never a legal excuse for anyone at any time.