It always fires and every round has the same exact marks. I’ll have to scoop it to see I guess.Does it happen if you chamber and don’t fire?
I suspect it’s a burr in the chamber and when the case gets rotated during extraction it scratches.
Or it could be from when it’s getting flicked out the ejector pressure smacks it into a sharp lug if it’s always on the ejection port side.
A bore scope and some slow inspection would highlight the issues source
It’s actually a Sako TRG 22 in 6.5cm. It’s been a crazy accurate beast going on 900 rounds now. This is the first I’ve seen this happen. Maybe stuck debris? Was gonna scope it or clean the bell out of the chamber with a bronze brush.It’s when the brass is extracted and slaps against the action. Try to remove the sharp edges in the action. Remove the barrel and stick your finger inside the action and feel any sharp edges. Could be a burr or the action was cut so precise and not dehoned it leaves razor sharp edges.
Or what @spife7980 said. I went through the same issue, had my chamber inspected and honed but the marks still appeared. Found out it was sharp edges in the action. A little dehoning of the sharp edges inside the action and no more cut marks.
Won’t hurt the brass it will develop the cut marks all over the brass the more firings you get.
What action you using?
Ahh gotcha, sounds like a good idea if it just appeared after 900 rounds.It’s actually a Sako TRG 22 in 6.5cm. It’s been a crazy accurate beast going on 900 rounds now. This is the first I’ve seen this happen. Maybe stuck debris? Was gonna scope it or clean the bell out of the chamber with a bronze brush.
If it's something sharp enough to cause this, it's probably something that won't "clean away". I recommend honing. HERE is the 6.5mm brush I use. Don't forget the oil ... both available on Amazon.It’s actually a Sako TRG 22 in 6.5cm. It’s been a crazy accurate beast going on 900 rounds now. This is the first I’ve seen this happen. Maybe stuck debris? Was gonna scope it or clean the bell out of the chamber with a bronze brush.