They do. You can open the gun up and completely remove the lock and the revolver will function fine but it will leave n empty hole in the side of the gun. Most who own them seem to have good luck on the lock not engaging itself under recoil, but some, in spite of what the factory says, have had issues with this happening. S&W calls this a 'storage lock' if that matters for legal purposes to you.

I personally will not trust one on a lightweight self defense gun...range toy is a different matter...but I am a bit of an old fart these days. I will take a standard, pre-lock M642 any day over one of the newer guns.