I have also seen that in a couple of Grendel’s and done this very thing to the ejector. Another thing that I do with pretty much all of my Grendel mags now is very slightly adjust the feed lips of the magazine to allow the round to release more cleanly. . It’s a simple adjustment that can be done in less than one minute. It allows the rear of the cartridge to clear and pop up just a hair sooner as the projectile enters the feed ramp . This helps keep the cartridge square to the chamber and bolt than before. A slight nose up attitude is given to help the cartridge clear the front of the magazine without making contact in with the front of the magazine which I also bevel and polish.If the rifle is jamming on feeding, here’s your issue. The top of the case (rim) is catching on the ejector. All you need to do is either remove the ejector and give it a good chamfer that the rim won’t catch on, OR, with a dremel, grind a slight bevel on the bottom edge of the ejector as it sits in the bolt. This will allow the back of the stripped round to ride up the bolt face and not wedge the live round with the rear stuck against the ejector and the bullet pointed up in the chamber with the barrel extension (bottom lugs) binding everything up. I’ve seen this multiple times with Grendel AR’s.