Why does loomis shoot the gun toward the second floor?

Loomis shoots the gun toward the second floor to confront the threat posed by Michael Myers, who has returned to continue his violent spree. His actions reflect a desperate attempt to protect others and stop Myers, believing that he needs to take decisive action to prevent further harm. The gunshot serves as both a warning and an effort to draw out Myers, showcasing Loomis's determination to confront the evil he believes is embodied in the killer.