I've had a Mossberg 500 "Combo Gun" for some time now, and recently picked up a 590 A-1 Mil-Spec. I thought it would be helpful to do a comparision of the features / price / and value of both guns because while both may appear similar, there are a few differences worth pointing out. First off I'd like to point out that isn't rust you're seeing in the pics. It is just very poor color saturation from my crappy Sony Cybershot camera. The "striped" appearance of the Parkerizing on the 590 are oil absorption marks that transferred from the case I had it in. PRICE The Mossberg 500 "Combo-Gun", as it is referred to by several of the big box stores that sell it today, runs right around the $249.00 to $299.00 range. The 590 A-1 Mil-Spec runs, (as you see it configured), around $460.00 to $480.00. About $160.00 to $180.00 more. FEATURES The 500 "Combo" comes with a standard anodized receiver and 2 gloss blued barrels. The barrel you see mounted to the weapon is the 18" cylinder bore with a standard brass bead front sight that is threaded into the barrel. The gun also comes with a 28" Vented Rib standard field barrel that has a fixed Modified Choke. It does not accept screw in choke tubes. Mossberg does sell aftermarket barrels for this gun that do have them. It has the standard synthetic field stock and forend. The gun has a standard 5 + 1 capacity. Both barrels have 3" chambers. The 590 A-1 Mil-Spec has a parkerized finish on all exposed parts. Barrel, receiver, and bolt, as well as the magazine tube are all Parkerized. The barrel is a 20" cylinder bore with a single brass bead threaded front sight. The magazine tube hold 8 rounds for a 8 + 1 capacity. It also has a 3" chamber. Other features of the 590 A-1 Mil-Spec Model are a bayonet lug that is threaded to accept a front sling swivel that comes with the gun, a heavy walled barrel, a metal safety button and trigger group, (the safety switch and trigger group on the 500 are plastic). The 590 A-1 Mil-Spec also comes in an all but limitless amount of stock configurations. Standard, collapsible, as well as Speed Feed and others are offered. There is also the 590 SPX Model that comes complete with the Ontario Knife M-9 Bayonet. Another feature of the 590 A-1 Mil-Spec Models are the dual barrel / magazine tube attachment points. As the photographs show, the 500 Models are attached by a single ring at the end of the magazine tube. The 590 A-1 Mil-Spec has a dual attachment system with two rings that are heavily brazed to the barrel. The barrel also attaches a bit differently on the 590. The magazine cap is completely removed, then the barrel removed. This is much like a Remington 870 in that regard. On the 500 the magazine cap does not completely come off. The actions on both guns, while not totally identical, are very similar. The manual states that barrels and internal parts will not interchange between the 500 / 535 / 590 Models. I haven't tested this, so I'll take Mossbergs word on it. OVERALL VIEW Both of these guns exhibit excellent value and quality for the price. Both are made in the USA. If a person is looking for the most for his money, the 500 "Combo" is pretty hard to beat. It offers very good value for the dollar. Especially considering you get 2 barrels with the package. I've had around 1,500 rounds through mine total so far, and have not had a single issue or problem. These loads were a combination of low brass target loads, heavy 3" Magnums, as well as Buckshot and rifled slugs. It ate them all with zero issues. The 590 Mil-Spec I just received this past Friday, so I have not been able to evaluate it's performance. Hopefully I'll get out to the range next week to run it through it's paces. If a shooter is looking for a well built, solid home self defense weapon, the 590 A-1 Mil-Spec would be a pretty difficult gun to beat. It was the only pump action, combat shotgun tested by the military that met Mil-Spec requirement Mil S-3443 which consisted of 3,000 rounds of Magnum buckshot with the gun being fully operational afterward. The other guns in it's class are more expensive when similarly configured. It appears to be a gun that can hold up to a lot of rugged use. I think it would be a hard gun to beat in the role of a home self defense shotgun. Which is better? At this point having not yet run the 590 A-1 Mil-Spec through it's paces as of yet, I would say based on features and price, the 500 "Combo" is the better buy, while the 590 A-1 Mil-Spec is the better gun. Either way I doubt you could go wrong with either.