I bought a used Colt 1911 recently. Series 70 I think. It looks "lightly" used to me. When feeding all lead round nose ammo and sometimes FMJ ammo the slide requires a little nudge to go into battery about every 6 - 10 rounds. It also seems to be throwing the brass a good distance away. I have not had any problems with jams of fired cases. A Colt a owned about 20 years ago would just about lay them at my feet which makes me wonder about the recoil spring. I am going to order a couple of new recoil springs. Probably a 16 and 18 lb and try these out. I would appreciate it if anyone had any advise to give as I have not fooled around with one of these pistols for quite a while.