I was able to loosen the spring action a bit and make the cartridges slide under the extractor easier as dahermit suggested. Now if I give a fast, vigorous push forward I can get a cartridge to chamber. But it's not 100% and anything less still binds. I also noticed large scrapes on the cases after they jam up, that appear to be caused by the mouth of the chamber. I have no experience with Mausers, so I am not sure what kind of tension or how well the rounds should stick to the bolt face with extractor pressure.
Also, I noticed that the rounds are not feeding reliably from the left side of the magazine. The case seems to move forward too far while still in the magazine and then pop free suddenly and the rim is not always caught under the extractor. Not sure if this is related or not.