Is it possible to put you finger over the chamber hole behind the revolver? Mine is modded so that the revolver swings out further, so I don't know if you could reach it normally. If you can, check to make sure it blows air out when you fire, or you may have a plunger issue. If it does blow out air out, make sure you are using Nerf brand darts, and that the barrels in the revolver are free of any debris or grime that could be blocking the darts.