I have a 1959 vintage Government Model that was bought used and lightly customized (sights, trigger, etc.) that digested 20,000 rounds without a malfunction that wasn't ammo related. Split case mouths would occasionally get by my quality control inspection and sometimes cause a failure to feed if the bullet set too far back during the feeding cycle. I quit counting at that point but it hasn't malfunctioned since then. I've owned several other 1911 pattern Colts that didn't malfunction but none of them stayed around as long as the above listed GM.
Owned a Wilson KZ-45 that I shot 4500 rounds through with no malfunctions. Sold it to a friend who still has it and hasn't had any malfunctions.
I also have a Glock 21 that I bought new and added a Bar-Sto barrel so I could shoot my cast bullet reloads. Counted to 20,000 and decided it too was reliable. Sold it when the G21SF came along as it fits my hand better. The new one hasn't malfunctioned either. I also have a 2nd Generation G22 I bought used and after adding a KKM barrel (for shooting reloads) has been malfunction free. I've only shot a few hundred rounds through it but don't expect it to malfunction either.
Wife has a Kimber Compact Covert Stainless that was bought used. It has never malfunctioned in probably 2-3,000 rounds. She also has a Glock 19 bought used that just works, no matter what you feed it.
My first duty gun, a Model 28-2 S&W revolver started hanging up in rapid fire DA after about 9 months of use and carry. Switched to a Series 70 Government Model and never went back to a revolver for duty.
Shot a Model 25-2 in revolver practical pistol matches for about 3 years. Shooting cast bullet reloads, I had to clean the chambers, cylinder face and B/C gap after each stage to keep it shooting smoothly and reloading easily. After 3 years of competition (all rapid fire DA shooting) the end shake, timing and lock-up all needed attention.
YMMV,
Dave