Seen mention of these, never seen one being used. Don't really care what it does for a .22. What it does for 5.56/223 is what would be interesting. I'd worry it would explode with 5.56. Obviously for chits and giggles vs any sort of alternative to a legit can, but .22* is a range toy also:



* I think he says .22, and recoil and noise seems like that to me.