The downside to movie guns is they get treated like lumber during the shoot. The barrels get a Blank Firing Attachment welded into the bore. The object is to have a gun that functions for the shot; not that will withstand a 6" inspection. The actors don't have to have PALs when they are under supervision of the tech experts and armourers. But the people who know how to handle the guns are out of the camera shot. Stuff gets dropped, banged, yanked and otherwise abused by the bright and beautiful folks.
Unless the director wants the gun firing in the shot, the guns in the background are props, ie replicas. We all know replicas are really really dangerous in Canada, and only a few blessed individuals or companies can own them.