I don't know whether this is a bug or an intended feature, but when I explode copper with TNT, it seems to duplicate the raw copper that comes from the copper ore.
Comments 3
Would MC-226552 happen to describe your issue? This report states that copper ore will drop multiple raw copper upon being mined. This was later resolved as "Works As Intended", so please let me know if this appears to be the case.
Could you add a little more detail to steps to reproduce?