sks ejecting very dirty brass

[u/Spiritual_Rope_6952]

i have a chinese sks, cosmoline all cleaned up, but when i shoot it (norinco non-corrosive) the cartridges come out all dirty with some kind of soot all over them. is that normal? otherwise it works perfectly and ive never had a jam. ive just never seen a semi auto ejecting brass so dirty before

[u/theawesomedude646]

i get the same but i think it's just burning the oil i covered the bore with for storage. either that or it's gas blowby from the steel cases