Having not seen the gun in question I can't be certain of course but it's unlikely the extractor is worn.. They don't start out as very much and are a chore to swap but in my humble opinion usually work. I see a lot of broken and not functioning stuff and the M700 has it's share but the extractor, puny as it appears doesn't give a lot of trouble. That said the rifle I built for my daughter stopped working on the opening morning of our firearms deer season a few years after it was built. The extractor wouldn't allow the bolt to close on a case. We swapped it for a spare rifle and I worked on it that evening. The problem, a piece of brass wedged Behind the extractor! I can only imagine a shaving(??) from the head of some prior casing but a small probe removed it and the rifle has worked flawlessly since. To reply I'd say this...as taught by an old friend,, if it ain't broke, don't fix it..