I owned a new SR1911CMD 4.25" .45ACP version of the Ruger from 2017 to 2019. I fired 11,800 rounds. During this time the following breakages occurred:
-Two front sights (Ruger replaced taking ~2 weeks each time from sending the slide in, to getting it back).
-One adjustable rear sight. This was a Novak adjustable rear sight which is the same as Ruger sold on its website, but I bought mine from a different online seller. The originally supplied fixed rear sight shot ~2.5" too low at 15 yards.
-One slide stop. The lobe broke off. Replaced with a Kimber-brand I had for spare parts.
-One extractor. The hook broke off. Replaced with a Kimber-brand I had for spare parts.
I also replaced the barrel bushing with an EGW barrel bushing. I wasn't satisfied with the accuracy ~7" at 15 yards. This bushing probably tightened the groups by ~30% (down to ~5"), but still not to my liking, before I sold the gun.
I believe the rear sight, slide-stop, and extractor would have broken with any 1911; with the Novak rear adjustable sight breakage being a fluke by having its usually staked-in adjustment screw coming loose while shooting the gun. I heard Ruger now has its 4.25" 1911 sighted in with a different height front sight. This should alleviate a need for a rear adjustable sight and might cure the front sight breakages (but I'm not going to try another Ruger 1911).