I don't know a great deal about the history of the Win Model 100. What I do know is that in the late 80s or early 90s, they were the subject of a recall. Some problem with the firing pin, I believe.
It was the firing pin. They have just about all been fixed. Once in a while some one will have one that wasn't corrected. Wisedner's ?? and most gunsmiths can fix them and they'll be re-imbursed by Winchecter and their new company. Anyone could replace the firing pin. It is a shame that Winchester quit producing them. Manufacturing cost was too high. Great guns, streamlined semi-autos with nice one piece stocks.
They got a bad rap as jammers. Jamming ocurred due to being dirty or having bent magazine lips. If kept clean and one didn't drop the magazine they were very reliable. Today, a lot of them have weakened extractor springs that cause them to jam. The case slips off the extractor before the ejector can kick the case out of the receiver. Replace the extractor spring and your good to go. I've replaced a half dozen of the extractor springs on 100's which cured their jamming. Bedding the action will significantily improve their accuracy. It has to be done in four steps. About five years ago, I posted the bedding process on this forum.