I myself stick to glossed plastic from well known brands and i've seen people trying cheaping out and end up catching the hopup rubber with some deformed mold fail bb then firing more and wrecking the gun internally. I don't understand it- the bbs are cheap as it is, better bbs fly further and more accurately really it makes sense to buy the good ones. Also BB Bastard are dead cheap and the best quality I myself have ever used (which isn't much but im sure others can attest) drop the cybergun they are pretty bad pickup some bb bastards.
if you really really wanna be a tree hugger they have bios.
Primary: TM MK 17 MOD 0, ICS L85 A2, Echo1 AKM, Echo1 AK-74, WE AK-74UN, JG AK-47 | Secondary: TM M9
Proud member of Force Recon