I've got a Savage 23AA that I'd like to get running. Last time I took it out I fired about 5 rounds and got some hot powder or metal or something hitting me in the face. Not sure exactly sure what it was. this time I'll grab a few different rounds to try and see if it was an ammo issue but I figured I'd see if anyone had ideas? Also it looks like someone drilled and tapped 4 holes on the left side of the receiver. Any idea this they could be for?