Running the Kak 10 oz. buffer right now.
No kidding. How does the ejector look?
Ejector looks fine. It seems like the bolt is just getting there to quickly. None of the casings had the same marks. They are just getting caught by the bolt on the way out every six shots or so.
I put in a spike 9mm buffer 8oz I believe and it ran much better. Also finished out the bottom to make it look less like a hodge podge of Parts (which it was) and more like a complete pistol.
700 rounds through it, 0 error. Very accurate. These Mean arms PMag adaptors run great!