I bought an 870 Super Mag when they first came out. Handled everything but the 3.5 inch shells. It would fire them but would lock up tighter than a squirrels ear to eject the shell. The inside of the chamber looked like it had tooling marks from the factory and I think the excessive chamber pressure with the 3.5 magnum shells would bind it up. I sold it to a guy I knew who polished the inside with a drill and solved the problem. I took it teal duck hunting when I first bought it and it was raining out. When we left I put it in the case and headed home. I kid you not, by the time I had gotten home it was already rusting. I don't know if they all did that but I could not believe it at the time. The matte finish on it was horrible.
When Grice first took deposits for the SuperMag, I gave them the money for two. When I bought my shotgun, I also reserved the next in line for my brother.
Since Straw Buys are illegal in Pennsylvania.My brother probably only fires 8 shot a year out of his and I hunt with mine - 60 days a year.
My brother probably only cleans his shotgun once a year and is lucky if it gets wiped down with a oily rag 5 times - all of hunting season.
Mine was oiled every day.
My brother had absolutely no problems with his, while mine was in the shop for a couple of months getting issues worked out.
I already have the black matte finish rubbed down to the blue, which his is still as course as a corn cob.
On the side of the action where the pins goes through that holds the trigger group, there is a couple of bronze areas where either they welded something or they held it while they machined it or blued it and if you let it go long enough it will rust.
To solve this problem, what you want to buy is LPS Lubricant # 2
http://www.labsafety.com/LPS-Lubricants-and-Rust-Inhibitor_24541922/We used this stuff in the machine shop where I worked to protect dies and some robotic arms that we made for Motorola that was for robotic arms that built satellites that traveled on the Space Shuttle.
You can buy this stuff in a non aerosol bottle and one bottle should last a lifetime. This is the best gun lube you can buy.