Does anyone know what this is? My friend found it at Home Depot around a bunch of nail guns when looking for pop rivets. I guess he didn't want to ask anyone there. He says they had ones with yellow caps and red caps as well. They are .22 rimfire rounds and we're both kinda wondering if they shoot like blanks, and the force is used to drive a nail in (as opposed to pneumatic nail guns). Anyone? Hopefully you guys can save me a trip to Home Depot cause I'm dying to know. They're stamped SuperX on the bottom.