Well, here goes. I was cleaning my TRG-22, and I shown a flash light into the the chamber area. To my horror, I saw machine machine marks on the edge of the chamber, or so I thought. Turns out that SAKO puts the caliber and serial number down there. So if you see strange marks around the chamber, that's what they are. Don't be an idiot like me and panic. I was so relieved. The rifle shoots like a dream, but that's kinda to be expected. Take care all