Every firearm I have ever fired from 4.2" mortars, 40 mm anti aircraft guns on down to pellet guns have malfunctioned on occasion. If you shoot one enough, get it dirty enough, get enough wear on it; it will malfunction. It may be ammo related, it may be magazine related, it may be worn out or broken parts, or it may just be so dirty that it can't function reliably anymore. In these discussions about handgun reliablity, what we are really interested in is whether the basic design of the gun is sound. That the malfuctions are not inherent in their design. The deisgner of the weapon has no control over whether you clean it, lubricate it, or shoot good ammo through it. That much is up to you. What matters is, if you do you part, will the gun do it's part ?
I have owned a number of 1911 handguns. I currently own three, a Colt Series 80, a Springfield Armory "loaded", and a Colt Officers Model enhanced. In the past I have owned Colt Series 70s, Colt National Match, GI Colts, AMT Hardballer, and a Auto Ordanance. I can honestly say that I never had a problem with the gun unless I didn't clean it, I didn't lubricate it, or a part broke. At one time I shot IPSC with a Colt Series 70. I was shooting in the neighborhood of 1500 rounds per week in practice and in matches. During that time I had extractors and ejectors go bad, once they were replaced and adjusted I was good to go for a large number of rounds. I had a few magazines go bad on me, I threw them away and the gun worked fine from there on out. During one of the extractor outages, I had a match to shoot on a Saturday. I stopped on the way to the match and bought a Colt Series 80. I removed it from the case, loaded it and shot a match with it. No cleaning, never even had it home. It functioned fine. I still have that gun and it works great. I was out with a guy one day sighting in his .454 Redhawk. I was taking a break from the severe recoil of that cannon and decided to see how my 1911 (the series 80 mentioned above) shot off sandbags. I had never tried the gun off the bench before and was amazed when I shot an 8 round group at 25 yards that could be covered with a quarter. This gun has had countless thousands of round through it and it is still running like a top. Every 1911 I ever owned was bone stock. No mods or aftermarket accessories of any kind; I even have the original grips on them. I am not going to make any claims for the 1911 being the most reliable gun ever made but I believe I have fired mine many, many thousands of rounds more than the average armchair commando and am totally satisfied with it's design. I certainly trust my life to any one that I have ever owned. What about parts breakage ? I mentioned several times that I have had broken extractors and ejectors. I personally don't believe this is a bad design. When you subject any gun to the pounding I was giving those two Colts, you are going to have to replace parts at some point. This is the same as our car tires. They are good for a certain number of miles. If we put the miles on all in one year and have to replace them, that doesn't make them bad tires. Since I stopped shooting IPSC on a regular basis, I have never had to replace another part on a 1911.
Edited: I have to take that back about the mods. I do have allen head grip screws in all of them.