^^
i own both Mossy 500s and Remington 870s. a Mossberg 500 pump is comparable to an 870 Express (they both have upsides and downsides) but available at a lower price with lower priced replacement barrels, so if inexpensive is one of your key criteria you cant go wrong with the $250 Mossberg. ive spent more money on a dinner.
Remington 870 Express:
-more durable steel receiver can be easily refinished and Park'd/blued however you like to match the rest of the gun
-easier to find/larger selection of aftermarket accessories
-shell lifter in the down position when slide is forward, making topping up with a closed action a bit more difficult (can pinch your thumb).
-approx 1/2" shorter receiver making it a bit more compact.
-crappy plastic triggerguard on the new ones
-non-removable magazine tube
-$325-350
Mossberg 500:
-lighter, aluminum receiver wont corrode but you are stuck with their crappy anodized aluminum finish forever. so if you park your barrel, mag tube, slide, etc like i did you are left with a receiver that doesnt match.
-much better safety location on the tang where it belongs, where it is activated by the thumb without having to move your trigger finger.
-shell lifter in the up position when slide is forward, making topping up the mag a little bit easier.
-two extractors vs the one extractor of the 870
-1/2" longer receiver, and the triggerguard starts exactly 1 inch forward of the back of the receiver (remington's is flush with the back). this gives every mossberg 1" extra LOP and possibly might make things difficult for people with smaller hands.
-crappy plastic safety and triggerguard (military upgraded these to metal on the 590)
-magazine tube is very easily removable (just unscrew it) for cleaning, refinishing, repair or replacement if damaged, or changing your gun from an 8-round to 5-round or vice-versa.
-$250
you might also want to have a look at the Mossberg 835. im not sure how these differ internally from the Mossberg 500s, however the 3.5" chambered barrel on these is overbored to 10ga bore dimensions, which would probably result in better patterns than any standard 12ga barrel. unlike the 500s ive never owned one of these, however - so i cant vouch for their reliability. the only thing that really interests me about them is the overbore barrel - you might want to look into them especially for target use where patterns are very important.
really though if you are only shooting trap/skeet and wont be shooting 3-3.5" shells just go to your local gun store and ask if they have any older 870 Wingmasters in stock. a lot of people sold their old 2 3/4" Wingmasters when upgrading to 3-3.5" for steel shot so you can usually get one for less than the price of a new 870 Express and it will be a much better gun than any recent production 500 or 870 Express.
i was considering one of the Mossberg semis for a new shooter, however, and it seems that the consensus is to go to a used Remington 1100, 11-87, etc or even the new Remington SPR 453. every thread ive read with people asking for advice on the Mossberg semis has had a flood of responses recommending something else - usually the Remingtons. that would be enough for me not to buy one.
