I've been running a test bed 1911, an auto ord that's running as much MIM parts as possible and nothing but steel cased ammo. So far, after 32k rounds, no malfs, no nothing but decent combat accuracy at 21 and 35 ft. I have noticed some extractor wear, but that's a simple fix from spare parts. Shooting this tula does require a very thorough cleaning, but then I'm a ret corpsman with 3 years fleet and 17 years with the USMC as a fleet marine corpsman, and I clean my weapons 3 days in a row after shooting.
I've been shooting the 1911 now for 45 years, and currently have 242 in my collection, not counting that worthless Llama 1911 that I bought in the 80s and still can't get it to work.
One 1911 I love to bits are my 3 norinco 1911s made out of reclaimed railroad steel. Beasts they are.
Thing is, if you shoot combloc ammo, give your weapon a better clean than you would had you used good brass cased ammo.
My auto ord went 3713 rounds before needing a cleaning to continue, whereas the same weapon using winchester target loads went 6138 rounds before cleaning.