I have the same problem hard to explain but I figure it out is to change a new long ejector and the problem goes away. (hence my old ejector has no damage).
Take out the upper receiver. Insert an empty magazine and wiggle it up and down (observe the movement with and without pushing the release magazine). If the magazine is too loose, that will create problems with feeding ammo because the magazine is too low (eventually resulting in a nose dive). This usually occurs when using a plastic grip 2011. Thanks!
I can only help you all 1911 and 2011 pistol.. I live in Adams blvd. Every 3rd Saturday of the month I compete Zev fun shoot @ Piru. If you want to meet me just let me know.
Try it again without using the spring that hold the amby safety and slide stop. It might be your spring that pushes the slide stop is a little bit strong..
With a little mods of casefeeder, I have 550b with Mr bullet feeder and dillon casefeeder I can loads 5 calibers 9mm,40,45,7.62x39 & .308 with no problem, 100 rnds/5 mins.