Found this gunsmithing video interesting when researching how to fix my "jammed" 642 Airweight. What to do when your revolver is jammed? - YouTube

When asked, S&W support discouraged taking my busted 642 to a gunsmith. The reason: If a gunsmith (licensed or certified matters not) messes up, the S&W warranty is null and void. The S&W solution: ship it to us for free manufacturer warranty based resolution.