My kid got sand in this blaster and i was tasked with fixing. i degreased the parts and used a plastic grease to re lube, but it was too thick for the plunger so the darts limped out the barrel. so i opened it up and used some fogging oil in there after cleaning it out. works a treat. The biggest problem was the little spring on the barrel.. I lost it 4 times, and the fifth it was gone. So i used a spring from a clicky pen and it works great now!