Well....I've taken it to my gunsmith twice for jamming. Basically what happens is the shell lifter does not lift the shell high enough so the bolt can push it into the chamber. As a result, the edge of the shell (sometimes the side, top, and bottom) comes in contact with the edge of the chamber, locked up the action. To allow the shell to go in, I have to bring the slide back a little and bring it forward again. At first I thought I was short stroking, but now it does this all the damn time. I have *never* had this happen with my M500. And just the other night, the ejector spring broke. This is what makes sure the spent shell ejects properly and far nough of the the chamber.
Well, my gunsmith called Remington in reference to the warranty and replacing the part. Come to find out the ejector spring housing it press riveted into the receiver. Remington advised they did not provide warranty on firearms 20 years or older (mines 22) and that if I wanted it replaced, they would have to comepletely reblue the receiver, because the machine that removes the ES housing would damage the finish on removal. And this procedure would cost me $150 bucks (according to Remington). Yeah, its FUBAR. Well, the gunsmith, with my permission, went ahead and removed the remaining ejector spring by breaking it off. As a result, my 870 will now function, but I still have the jamming problem and the shells barely eject far enough to clear the action. Anyways.....lol.