Yeah, they're legal in the states if you get the 37mm model. They launch flare, smoke, and CS grenades. Also if you have some machine skills you can make a sleeve and shot 12 gauge shotgun shells. That's illegal though. It falls under a AOW (Any Other Weapon). That's a $5 transfer tax and a BATFE Form 3 that you need to handle. The real military 40mm model is a DD (Destructive Device). That's a ton of paper work and being really friendly with BATFE.