Used during the fight with https://vanillawowdb.com/?npc=10997 Cannon Master Willey . It must be loaded with https://vanillawowdb.com/?item=12973 cannonballs from the nearby https://vanillawowdb.com/?object=176215 stacks and used to fire on the https://vanillawowdb.com/?npc=11054 Crimson Riflemen that spawn at the end of the hallway.