This is intended to be a comprehensive comparison of the Mossberg 500 versus the Remington 870. I'm dissatisfied by how shallow the comparison articles online tend to be, and the topic is too complicated to simply be covered in a simple comment every time someone asks the question. I will be refraining from the logical fallacies that people use to justify why one is better than the other – “Mossberg 500 is the best selling pump action shotgun for a reason!” “The 870 is the original, and more of them have been made for a reason!” “Mossberg didn’t sell out and is still family owned!” Hopefully this can help people who are new to shotguns and can’t figure out which pump action they want.
I am sticking strictly to the facts to make this as objective a comparison as I can.
Both of these guns are excellent pump action guns. Both have massive amounts of aftermarket support. Both are very reliable. Both are reasonably simple, lightweight, and versatile. Both can be set up to excel in hunting, competition, home defense, and combat. No matter which one you are buying, I strongly recommend your first gun be used, it’s cheaper that way and you can shop around to find the exact configuration you want.
Disclaimer: I own 3 Remington 870s and 1 Mossberg 500. I carried an 870 as a service weapon. I grew up with a Remington owning father, I learned to disassemble and clean a gun on an 870, the first thing I shot was a Nylon 77, and I personally prefer the 870.
Notes about the Remington
There are three main models for the 870 – Express, Wingmaster, and Police Magnum. The Express is the bare bones model, the Wingmaster is the higher-end "Cadillac of Shotguns", and the Police Magnum is designed to be low-cost for police departments without sacrificing quality.
Costs were cut in the Express by using the cheapest version of parts, and eliminating as much human labor as possible, which means it is not deburred, rough edges are not smoothed, and rough surfaces are not polished, as they would be in a Wingmaster. Originally, most of the Express cost savings were through skipping the deburring and not having to polish the outside of the metal, since a parkerized finish would be applied. Wingmasters had to be polished inside and out, so that the bluing would shine nicely. Today, the cost-cutting parts also includes the trigger group and the extractor.
The trigger group sits on a plastic chassis with a plastic trigger guard. Generally this is fine, and is just as durable as a metal one, but many don’t like it. If you often drop your shotgun in sub-zero temperatures, or you often run your shotgun over with a truck, then you will find the plastic guard less durable. For all other users, any difference in durability will not be noticed. Many users actually prefer the plastic trigger guard for hunting as a bare finger on a plastic trigger guard will not get cold as quickly as a bare finger on a metal trigger guard.
On Express models since 2007, the extractor is made with a process called MIM, or what anyone else would call “die casting”. These are generally lower quality than a billet extractor machined from a piece of metal. MIM extractors wear out much faster, and are typically not made with as tight of tolerances, so they can be defective out of the box. The vast majority of shotgun owners shoot less than 50 rounds per year. If you are part of that group, you are not likely to ever notice a difference in the MIM extractor, and this is why Remington can get away with using them. If you shoot more than that, you would do well to replace the extractor with one from a Police Magnum, or an aftermarket extractor like Volquartsen. Express models typically also have plain looking furniture, often uncheckered wood or low-cost synthetic stock and forend sets. From 2007-2018, Remington 870 Express models had significant rust issues. This is caused by salt used in the finishing process being improperly washed out. The official fix is to remove all wood and plastic parts, boil the rest of the gun in water, and then oil it down. In May of 2018, Remington emerged from bankruptcy yet again and the new ownership took measures to fix many of the notorious quality control issues, including the rusting finishes. From mid-2018 on, Express models have not had this rust issue.
Remington 870 Wingmasters, marketed as "The Cadillac of Shotguns," receive a higher level of finishing from the factory. Rough edges are smoothed, machined parts are deburred, and the exterior of the gun is polished so that the bluing can have a shiny finish. Wingmasters typically have a nice checkered wood furniture set, though they can sometimes be found with "corncob" forends or "trap" style stocks with a raised cheek rest. Wingmasters in recent years have also used the MIM extractors, but still use a compressed aluminum trigger group chassis.
Police Magnums by default are chambered for up to 3” shells, whereas Express and 870 models can be had in 2 ¾", 3", and 3.5" chamberings. Police Magnums have non-MIM extractors, metal trigger group chassis, and are built on a separate production line from other products with a significantly higher quality of production, as well as extremely strict levels of quality control. Police Magnums receive the same smoothing and deburring that Wingmasters receive, but the exterior is not polished as the finish is typically parkerized. Though most 2007 and newer production Remington products are of lower quality than past years, quality on the Police Magnum models never faltered. Someone on the used market can buy any year of Police Magnum with confidence. It is important to note, however, that buying a new Police Magnum is very difficult, as dealers would be in violation of policy by selling any brand new Remington Defense product to a member of the general public.
There are other 870 models such as the Marine Magnum, essentially a Police Magnum with a saltwater-resistant nickel finish that is available to the public; the Tac-14, a 14" barreled shotgun designed to skirt NFA regulations; the Hardwood Home Defense, an Express with bluing applied to the unpolished exterior to create a vintage appearing matte bluing; and many more, but these three main categories summarize the most common models available, and then some.
Notes about the Mossberg
This section is smaller since the differences are not quite as complex.
The Maverick 88 is the economy model. The 88 has a safety design similar to the 870. Maverick 88s are typically found with a parkerized finish and synthetic furniture, though Mossberg has marketed "trench gun" appearance Maverick 88s with plain uncheckered wood stock and forend sets.
The 500 is the basic model but does not cut corners in quality like the 870 Express. It is sold in many different configurations, including blued, parkerized, wood furniture, synthetic furniture, there are many different barrel options and it can be chambered for 2 ¾", 3", and 3.5" shells.
Technically, a 500 receiver could be put on a collection of 88 parts, or an 88 trigger group could be put in a 500, but a 500 trigger group in an 88 receiver will result in a shotgun that functions but has no safety. This should never be done. All other parts are freely interchangeable.
The 590 is an 8-shot, 20-inch barrel model. To my knowledge the 590 does not have any other barrel lengths available. The 500 and Maverick 88 can be converted to a 590 barrel and magazine tube setup, but this limits them to only a 20 inch barrel option. The 590A1 is a military and police model with a metal trigger guard, a heavy barrel (requested by the Navy to prevent the barrel deforming if squished by a ship’s door), a bayonet lug, and can be ordered with 14, 18.5, or 20 inch barrels. In the 20 inch barrel, the magazine tube will hold eight shells. In the 18.5 and 14 inch barrels, the magazine tube will hold five shells. The 590SP is a 590 with the A1’s trigger guard and barrel. For marketing purposes, the 590SP is often called a 590A1.
Mossberg markets their Shockwave line of short-barreled non-NFA shotguns as a 590. The 590 Shockwave is a 590 in name only.
Receiver. The 500 uses an aluminum receiver, while the 870 uses a steel one. The 500 barrels are generally heavier than an equal length 870 barrel, but the aluminum receiver makes an equal-length 500 still lighter. Due to the weight difference, a 500 will cause less fatigue for the person carrying it, and the 870’s weight will absorb more felt recoil than the 500. However, these effects are likely to go virtually unnoticed by the user since the difference is only a few ounces. The aluminum also means the 500 receiver will not rust even with the finish in poor condition. A steel receiver is of course stronger, but conditions in which this strength would be needed are unlikely to be encountered by the vast majority of users. The other effect of this is that the balance of an 500 makes it marginally more forward-heavy than the 870.
Safety Design. Something that often draws left-handed shooters to the 500 is the safety design. Being naturally ambidextrous is attractive. The standard 870 safety is designed to be disengaged with the right hand’s trigger finger, so it is difficult and awkward for a left handed shooter to manipulate it, which is a problem when reaction time is critical. There are trigger groups available for the 870 that have a reversed safety, so that the safety is disengaged by the left hand’s trigger finger. There are also many reports of the 500’s safety wearing out until the recoil of shooting the firearm will engage the safety, requiring replacement. Unfortunately, many users “fix” this by filing the safety down so that it no longer functions at all. Both models are also available in a left-ejecting configuration, which uses a unique barrel design that is not interchangeable with right-ejecting models. It is also important to note that the "ease of use" on the Mossberg safety design is lost if the gun is converted to a pistol grip setup, as the pistol grip position puts the tang out of reach of most adult thumbs.
Trigger Pull. Stock trigger pull on the 870 is supposed to be 5.5 lbs, while the 500 is supposed to be 8.5 lbs. I have found parts on the market that reduce those pulls to 3 and 4.5 lbs, respectively.
Action Bars. All 870s have double action bars from the pump handle to the bolt. Remington had a patent on this design which forced Mossberg to use a single action bar until that patent ran out in the 1970s. The Maverick 88 continued to use a single bar until 1990, as a cost cutting measure. This is a weak point in the Mossberg design, but 500s and 88s with double action bars are so plentiful as to make it nearly a non-issue.
Extractors. On top of the MIM extractor concerns, 500s use two extractors, while the 870 has just one. Additionally, 870 extractors are more difficult for inexperienced users to replace (which often leads to the entire bolt being replaced, which is easier) while 500 extractors can be swapped out easily, if either ever broke.
Magazine Tube. The stock 870 magazine is 4 rounds, and the stock 500 magazine is 6 rounds. On the aftermarket, kits exist to give the 870 a vastly expanded magazine, no matter the barrel length. For the 500, the only option for higher capacity is to convert to the 590 8 round tube, which limits the gun to a 20 inch barrel. This is the key difference in customizing the 870 versus the 500.
Aftermarket. Aside from magazine tube capacity, most aftermarket parts available for one are available for the other, or at least an analog of that part.
I hope this has helped anyone trying to shop between the two models. Feel free to send me a message if you notice any inaccuracies or have any questions.