I have been tinkering with 1911s for 20 years now and have ran into something I’m unfamiliar with. Long story made short; dog ran off with slide stop from a new STI single stack USPSA model. Ordered a new slide stop. After installing new stop I noticed a slight “bump” when the slide is about 1/8 of an inch out of battery. This doesn’t stop it frfom going into battery and can only be felt when moving the slide in and out of battery by hand. I found the old slide stop and after installing it I found this doesn’t happen. Reinstalled the new stop and the same problem again. Its not a big deal I can just use the original but it drives me crazy not knowing what’s happening. Could the lower lugs be dragging on the slide stop pin just before lock up?