boomerxm, I don't know much about 1911's, and I haven't fired one in about 50 years, but I'm replying, because I think I'm offering better advice than the other sarcasmic(sic) posters.
If you have too strong of a recoil spring or the slide is binding on the frame, the frame might not be going back far enough with enough force to eject the brass. Also, if you have too weak of a recoil spring, the slide can bounce back before the brass has time to eject. On the only handgun I've fired in decades, I created this exact problem (on purpose, I studying it) by both using too strong and too weak of a spring.
You have greased the rails, haven't you?
How's it feel when cycling it by hand? Any binding, especially between the barrel and the bushing?
Are you sure you're gripping it strongly? The first time I fired a 1911, I had it jam on me every single time, until I was shown how to hold it. That was the first time I had fired a handgun, and I didn't know any better. After I started holding my wrist directly behind the frame, the problem went away.
Also, how does the ejector look? Again, it's been decades since I've looked at a 1911, but from what I remember, a few officers had trouble with the top edge of the ejector breaking off or with the ejectors wiggling too much in the frame. You might want to look in a catalog to see how a new ejector is supposed to look to make sure yours has the correct profile, and make sure it is tight.
I think a weak extractor spring or bent extractor could cause this problem. It might not be getting a good grip on the rim on the case. Also, the hook on the extractor might be misshaped or chipped. The extractor might not move smoothly in the cut-out in the slide. Does it move in and out without binding? Even on a very nice, high-quality new Springfield you still could run into trouble with this. I know a few Colts we had had burrs in this channel.
Ejection port. I remember seeing several officers with the ejection port filed on the bottom edge and back edge. It didn't look like much (0.1" maybe), but it was supposed to help keep the slide from knocking the brass back into the pistol. This might have been an "old-wives" tale, because there were a lot of things we did there for reasons that weren't rooted in reality.
Shooting way too low? Other than having a sight with an incorrect height, I don't see how it could be shooting that low. How do the holes look in the paper? I have a Kel-Tec P32 that didn't have the finishing process done on the inside of the barrel (no rifling!). It creates some nasty looking holes in paper, and shoots about 18" low at 25 yards. Are your holes round?
Again, the above consists of my wild guesses. I'm not lucky enough to own a 1911 myself, so I'm sure that you'll get a better response from someone else when they post to disagree with my advise.z