My KX-5 would "catch" the brass shell head on the chamber mouth when I closed the gun if I used Remington hulls - it wouldn't do it with Federal shells because of their higher brass head. Krieghoff International basically shortened the travel of the ejector a little so the brass was already slightly inside the chamber mouth when the gun was closed.
The culprit is usually the firing pin hole. The bottom edge gets sharp and as the curved edge of the shell passes by a small shaving of brass is cut from the bottom edge of the shell brass. Any competent gunsmith can relieve this sharp edge with a small stone or burr.
i had the same thing happen to me....norbert fixed it at san antonio.....the firing pins to through a "block" that is fitted in the receiver .... if the round ends don't fit properly and sit back just a hair..a edge from the receiver becomes apperent....my shavings came from the top shell...you'll have to have krieghoff or a train gunsmith work on it.... p.s. it does'nt matter if you use cheap or over priced shells..if the face is not even you'll shave brass
Had it with my Guerini right after I bought it. It was the resizer not tightened down enough on my MEC. Measured a new shell and a reload and there was about 0.010" difference. Shrunk the reloads a bit and no more problems.