So I have a co worker looking at buying a 9mm M&P and is debating buying a new, never fired pistol from a private buyer, or buying a new one from a dealer. Whats S&W's policy for warranty, original owner only? First person to register it? Lifetime on unmodified firearms? If the latter, I am GUESSING things like different sights won't affect that? Sorry for askin a noob question but, I searched and really didnt see an answer for this .. thanks in advance..

Well, the manual and/or warranty statement says the coverage is for the original owner.

From the S&W website:

"We will repair any defect in material or workmanship without charge to the original purchaser for as long as you own the handgun." (I added the bold for emphasis.)

However, many here have called S&W with an issue and they were never asked if they were the original owner...S&W just accepted and serviced the pistol. I'm not suggesting that anyone should be dishonest...but S&W isn't apparently too concerned about it. I would imagine that if someone gets snotty with them, though, they could get real picky about the rules.

Unless the used pistol is a good bit less expensive than the new one, or the seller is a good friend you are trying to help out, buying the new one with the assurance of the lifetime warranty would be my preference.

S&W has fixed second-hand guns free, under warranty, for some, but not for others, and the oness they have done free were probably done out of the goodness of their hearts/desire to foster good customer relations.