Actually, our players are against FPS over 350. It's just my friend thats a bit crazy heheh.
No legality problems at joules here, as long as the gun isn't shown in public or used for bad purposes, it's cool. Our customs are a bit problem though, especially with replicas of turkish army weaponary, without a huge orange tip it's really hard to pass a rifle that is also used in the army.
Airguns that shoot over 1000 FPS also doesn't require license, but if you dare to hunt with them (shooting birds for example), or harm someone, you are in deep deep trouble. Same goes for airsoft, shoot at animals, it will be considered as illegal hunting.
Talking about fps over 600.
This one was at 650.
Some parts were custom made, full metal.
It costed over 5000$ to build it. It was quite old too, before all those good upgrade stuff.
It got stolen :/ never to be found.