ICS just released their new (and heavy) 8mm (+- 0.02mm) BBs, they come in white and 0.48g. They are the origional competition grade BBs. Check out their promotional page at http://www.icsbb.com/

Features of the ICS 8mm BBs
Spec:0.48g / + - 0.02mm

ICS extremely precision and premium polished 0.48g 8mm BB is out. ICS 0.48g 8mm BBs are produced in ICS factory in Taiwan, same as ICS high quality 6mm. Therefore the quality of 8mm BBs is same as the ICS high quality 6mm BBs. ICS BBs is the highest quality with reasonable price for your airsoft guns. Although the roundness of ICS BBs is almost perfect. However, ICS would not exaggerate to promote our products. We are responsible to what we say and we ensure the tolerance in +- 0.02 mm. You must try ICS 8mm bbs to know the power difference between 8mm and 6mm bbs.