As many have already said, the 870 & 500 are great guns that should give you many years of service. You may also want to look at the H&R Pardner shotguns. It's a lot of gun for the money and from what I've seen, they're very well made with good barrels. They also accept the Invector/Win-Choke threaded chokes, so you have a lot of choices.
"If he's out of range, it just means that he has another day and so do you."