That's cause I took one (3 actually) for the team.
Have had two bolt handles fall off and 1 extractor break. The extractor didn't really break but something happened to it such that it wouldn't grab the case rim any more. Oh, I remember, it twisted around in the bolt face. Anyway, it didn't work and I needed a cleaning rod to get the case out. Replacing the extractor cured that problem.
I've also had the ejector pin get jammed up several times by a sliver of brass sheared off by (variously) burrs or a raised lip around the ejector pin hole, or brass shaved off by a too sharp extractor hook. It extracts the case okay but it just sits there held to the front of the bolt, you have to reach in and flip it out with your finger. That is, if you haven't tried to load the next round and gotten everything jammed up. All you have to do is get a screwdriver tip or something and push the ejector down a couple of times to work the brass shaving loose to fix it.
Usually these problems are caused by shooting loads well over-pressure.
I know from experience
First one I saw was a pre-stainless period rifle that had only fired factory Core-lokts; second was a stainless rifle which was quite new and the bolt popped off when the bolt was closed under the tension of the firing spring. (The trigger was pulled when closing the bolt - my bad!) I have two I use quite often; both have been shot enough that they have proven themselves to me. I don't think the design is a bad one- only the execution at times.
Sometimes, the air you 'let in'matters less than the air you 'let out'.
