Zamak and imitation wood ie plastic. CO2 has its uses, but bbs are crap to shoot.

Sounds like a very expensive toy to me. If you want it for a wall hanger, you'd be better off with a decent a deact.

For 400 quid you can get a HW77 in a laminated stock - steel, wood, rifled barrel, spare parts readily available, and guaranteed to last a lifetime.

Even a half decent pcp.