Shooting my new Glock 26 I keep getting popped in the forehead by brass from the last round of a full magazine. I actually had on shell lodge between my safety glasses and flesh a few days ago. I have a nice burn as a result. In contrast, sometimes the last round's brass sort of pops straight up a few inches in the air and lands back in the chamber. So, sometimes the brass flies with a vengeance. Sometimes sort of sputters out of the chamber. I'm not limp-wrisitng and hve a good solid grip on the gun. Ideas?