Last weekend I was out shooting with a friend and noticed a lot of the brass ejecting from my AK-47 was taking a pretty good hit on the way out leaving a dent in the case. I have had it about 20 years and it's had a few thousand rounds through it. I don't recall it happening before. It was one of the rare times I used brass casing with box primmers. I have a couple of thoughts on why it happened but as they say two heads are better than one unless both are attached to the cockroach in the White House. Gas tube? Spring? Ammo? Maybe someone has a way to narrow it down. Please feel free to put your two cents in.