made of bronze-yellow colored metal??
but its less derpy looking when pure yellow since blockland doesnt support materials with different reflectivity and texture? (not textures, but actual texture)
Aka brass. They use this because they dont corrose and its cheaper than lead iirc
Well it depends because most shotgun shells are plastic and even some are made from steel or aluminium. But brass is most common.

You should try a dark gold with a copper colored head.