definitely common sense, uncle was blinded in one eye by a foolish person being stupid with one, but i'd agree with Bolter, just common sense, if they licence them would just give them a reason to make it a more expensive sport.
Looks like your going to get one ? make sure you have a Barrel Sock to cover the end of your barrel for Safety Reasons,
Do not get a Bung and if you get a gun that has one ? throw it away and get a SOCK.
With many sites, this is a must and if you don`t < you`ll find out pretty quick. .. because the bung can be fired !!