If it's any consolation Yamin151, while you have one stubborn boundary-pusher, I seem to have ended up with 5 of them
Have you tried your son with 'riskier' sports such as skateboarding, stunt-scooters, or wall climbing/canoeing/biking etc?
Ds2 needs these and he also needs his freedom a lot so I know where you're coming from.
I absolutely hate all toy guns but allow toy swords, and we have an umbrella stand full of them (there is no logical reasoning to this so please don't ask for any!) but unfortunately somehow ds2 acquired quite a few nerf guns when younger, and repeated attempts to send them off to the charity shop have failed. Ds3 and 4 play with them now. It is not unknown for me to be modding this site with two large nerf guns firing at my head