02-14-2015, 05:34 AM
Not sure if this is the right plase to post this but. Shot my Grendel today for the first time an all the empty brass has a flat spot on the case mouth. Al were factory Hornady 123. Brand new gun. Sun Devil upper/lower with adjustable gas key Walther barrel. Not sure what could be causing this. Maybe slapping reciever on ejection??

