I have a Stainless Gold Match II - 1000+ rounds (exclusively lead SWC reloads) with zero issues.
I had the exact same problem with my new super match when I got it. Found that the Swartz "push rod" was too long and sticking up out of the frame by 0.015" with the gun at rest (grip safety not pushed). Removed the push rod and trimmed off 0.015" from the end, no problem since....I've got a couple Kimbers. My carry gun is the Grand Raptor II. It works 100%, but that wasn't always the case. When I first got it, new, I couldn't get the slide off of the frame. Yes, I know about the grip safety. There was just no way the slide was coming off. The Swartz firing pin safety was hanging up and just wouldn't let the slide move forward, no matter how held the gun. I made double sure the grip safety wasn't engaged.
I have a Kimber Gold Combat, not the II version. DO the C&S parts drop in, or do they require fitting? The trigger is so good, I hate to mess with it until something happens. Would like to replace all the MIM parts eventually.