Most of this has probly been mentioned but im goin to add my two cents, I also own a norinco 1911A1 sport, that oil that was on your gun when you got it is not really gun oil, its packing oil for shipping, you should have completly disasembled the gun and take out all the springs, dont forget the plunger tube spring as well as hammer spring, then soak every part in gun cleaner, like hoppes or i recomend M-PRO 7, hard to find but its non toxic no odour and works awsome, wipe everything down remove all traces of sludge, then lightly oil everything again i recommend M-PRO 7 oil. reassemble the gun.
Do the same to the magazines disasemble them but before you oil look inside the mag you should be able to see a very rough weld running the length of the inside of the mag get yourself a file and some 400 grit sand paper and make that weld smooth, the amunition does not like to slide over rough surfaces also the mag follower will catch on this seem weld and will cause failure to feed now you should also polish the edges of the follower itself to help it slide up the mag without catching and digging in.
i only use fmj or ball ammo mostly blazer, this will give you the most reliability because thats what the 1911 was built for, theres lots of info on the web about the 1911 learn everything you can. knowing is half the battle, i recomend polishing the breech face, feed ramp, and extracter look it up.
also getting yourself some MEC-GAR mags from Marster is a huge help for reliability these mags are perfect out of the box no polish needed, wolfe springs are also a huge advantage and cheap upgrade from those chinese springs that are in your gun, and your mags, if you dont know what your doing take it to a gunsmith they can install springs for very little money
Norinco 1911's are good guns they just need a little TLC even out of the box read and learn all you can about the 1911, again dont use hollow points or winclean truncated cone ammo only fmj and you shouldnt have many problems.