Faster action better built.

I have both and I still prefer my 870. I also have a benelli. I have put 10's of thousands of rounds through all three and when it comes to hunting I almost always grab my 870 for most applications. I like the weight, smoothness, and feel of the 870 over the other three shotguns.

AAM

To answer your question, you have to go back some years.

Back in the 50's, THE pump gun of the century (Win M12) became cost prohibitive to manufacture. The Rem 870 had already been on the market for several years and was soon embraced as the "next best thing".
Mossberg was a "cheaper" gun. And when I say "cheaper", I mean "REALLY" cheap.
The receiver was "pot metal" and parts were "stamped" with a stock that reminded one of a #2 pine 2x4! The receiver was painted because the pot metal would not blue.. I was a cheap piece of crap.

The Rem 870, still had a steel receiver and though they used stamped "guts", it was a higher quality stamped part. Wood fit and finish was very nice

I've owned two in my life and had disliked both.These were from the mid '70's. Both had thick pistol grips, ugly wood, cheap metal. I noticed 2 tiny splits(one was almost too small to see) in the barrel just behind the rear sight while hunting deer with the second one. It had all of 10 shots through it. I know that was a freak thing, and that they are much better now, but I don't care for cheaply made firearms. I do know many people that love their mossbergs, and to them, I keep my thoughts to myself.As far as a Remington 870, I'd only want a Wingmaster, if I were to buy one.

funny you guys are saying never jams as if the 500 always does. Mine never has. Also the 500 along with a Benelli is the only two shotguns that meet military specifications as is not adjustments. So yes in price the 870 may be cheaper but my 500 has never failed and continues to be a battle tested platform. So if its good to take down terrorists a few birds every weekend will be no problem. I have talked to guys that used the 500 in Iraq and say they worked flawlessly. So I will pay a few dollars more and get another 500 when my taxes come back. Plus the safety is right where it belongs. On top.

I like the feel of my 870 more. The 500 is a great gun but I just don't like the way it feels when I hold it.

I think it is a Chevy/Ford question. There are enough different styles of each to please everyone and they both shoot. My brother has shot the Mossberg 500 his whole life and I've shot the 870 Wingmaster. The looks of the Wingmaster were what drew me to it originally but its balance and reliability is what caused me to get rid of all my other shotguns. You will be quite happy with either of them in the field and if someone outshoots you it will either be your fault or they are shooting a shotgun that costs around 4 times as much.

As some others have mentioned a lot of it has to do with the Mossberg quality issue of yesteryear. To me an 870 always felt,pointed and swung better than the Mossberg. Over all appearance, fit and finish and quality also seemed better in the Remington.

But I'm in no way knockin the Mossberg. I figure you should shoot what you like. I've hear guys bashing Red Labels all the time but I've had nothing but great luck with them.

Also 870's,without modification, have seen more than their share of military and law enforcement service.