well I send my 935 waterfowl off to Mossberg to be converted in to a waterfowl Pro. I had already bought the boron nitride piston and return spring tube and the SS return spring. Well got a email today it is being sent back . Well I never paid for the other parts boron nitride Mag tube, boron nitride sear, and not pay for the installation of all the parts. I called and asked they said yes they did install all the boron nitride parts. She said boron nitride Mag tube replaced the trigger assembly with a boron nitride sear. She said it all was covered under warranty. So needless to say I made out like a bandit.