Why would one want to blueprint a M700 action and add a M16 extractor?
In some cases some smiths don't do anything to rem actions but most do square the boltface, lap lugs, square action and true threads. This all can improve accuracy. Sometimes the action is good enough. If I am going to spend the money to put a once in a lifetime gun together I will have it done or go with custom. One thing to remember most all of the custom actions are Remington clones so there is nothing wrong with the 700. I have factory rems that shoot really well but could be better. The M16 extractor is added to rem 700 to handle pressure which is a safety issue.