After recently reassembling my JG after a good internal clean, and washing the hop-up buckling, I put it back together and test fired it. Its firing perfectly straight and fine. But after inspection of the BBs I noticed that my gun is grinding off small parts of the BBs leaving scuffs on parts of them. I don't know if this is damaging to the gun or its hop-up so i was wondering if anyone could inform me of what my guns problem most likely is, and hopefully a way to fix it.