Got it back from Mossberg just less than a week ago.
I disassembled it immediately and could not figure out what they had done to it, if anything. The only paperwork included in the box was a half sheet of paper that spoke of cleaning the gas piston.
I called Mossberg and they said that they'd replaced the gas piston as it was defective. I found this strange, since the gun had no problems extracting and ejecting spent shells.
The problem was, and remains, that a new shell is not always released from the magazine tube.
As I stated in my previous post, the rear shell stop had an odd ridge along the lower edge that is not present in 2 other 930s that I've inspected.
That "rear shell stop," to the best of my knowledge, was not touched while in Mossberg's posession.
I do no believe that the tech ever looked at the detailed description of the failure that Mossberg asks you include in the box with the returned shotgun.
It's slated to go back, again, but this time Mossberg is paying for it. However, I'll try to shoot a match before it goes.
God gave you a soul.
Your parents, a body.
Your country, a rifle.
Keep all of them clean.