Thanks for the input Nitesite and everyone. I took my gun to a Mossberg approved dealer today after calling Mossberg and sending them the photos. First they wanted me to ship the barrel to them in Texas, but after they found out I'm Canadian they directed me to the nearest dealer they work with. The gunsmith explained the rust color as a chemical, and the straight lines I can't remember what he said those were, but he said it would be fixed with a simple cleaning and he took it in the back and cleaned out the barrel for me and it looks perfect now. Thank God.
I've certainly done my reading up on this shotgun so I know this is pretty much the best tactical shotgun money can buy. That being said it's very reasonably priced (I paid $694.00 after taxes). But to me, Mossberg isn't the best run company. They make some great guns, no doubt about that, but their customer service could use some work.
There are several variants of the 590A1 and the user manual is very general and does not get specific about problems that may relate to a particular model. Getting the buttstock off of this gun was an adventure in and of itself. I wound up about 75 miles from home in a barn in the country, with a gunsmith who finally got it off for me. Now. Had I known what to do (this is where the model specific manual would have been helpful) I could have easily done it myself. But the fact that I needed an AR15 stock wrench and the worlds smallest allen key were not something that was explained or even mentionmed in the manual.
I've had to deal with the guys at customer service at Mossberg twice and both times it seems to me like they are guessing when they give me an answer about something. They always speak in a non-definite mode, as if to always give themselves a back door just in case what they said was wrong.
Today, with the barrel problem. They wanted me to ship the barrel to them in Texas (until they found out I was Canadian) and they wanted ME to pay for it, without re-imbursement. I told them I hadn't even fired a single round yet, yet still he said I had to pay for the shipping. This is absurd. If any gun maker screws something up, doesn't check it before it goes to a store to be sold....and then the customer is the one who finds the mistake that QC missed......why should the customer have to spend any money?? After arguing with the guy for about 3 minutes he finally conceded and agreed to send me a pre-paid shipping label, but he sounded pretty annoyed at me, even though I was being completely logical (and polite too).
Mossberg is a great gunmaker, but I think the CS could use some work. Just basic stuff.
Anyways......I think all is well and now I look forward to giving it a good cleaning and getting out to the range. Thanks for all your help guys.