For some reason, you can buy the current 442 with or without the lock. When I ordered mine several years ago, I specifically ordered one without the lock. It's likely the only revolver they offer where they give you a choice.
Yeah, I don't get this... if they can offer the 442 without the lock, why not others?
edited to add; If they did, I would buy more new S&W's vs. just pre-locks.
Jerry