Horror movie logic:
Oh look, a gun! Oh wait, jammed slider. Finally unjammed it. Oh wait, no ammo. Not even a magazine. Oh look, a magazine! Oh wait, its empty. Oh look, a bullet! Oh wait, it's a blank shot. Oh look, a real bullet! Oh wait, slider's jammed again. Slider unjammed. Oh wait, the magazine spring won't work. Oh look, a different magazine! Oh wait, wrong caliber. Oh look, a good magazine! I finally loaded the gun! Oh wait, the trigger is broken. *dies*