The one thing that I'm not impressed with, is creating an exit hole by "shooting" it out. It seems to me that as the bullet impacts the end of the oil filter, it distorts as it strikes the sheet metal, making an innacurate aperature. The next round runs the risk of grazing or contacting the sheet metal, causing that round to go off target. That's two rounds expended so far, and if the whole idea is to quietly shoot something, especially at range, you run the risk of being off center and have quite possibly blown two attempts.