The Remington Model 870 shotgun is one of the most iconic modern firearms still being manufactured. Used by the military, law enforcement and civilians since 1950, it was designed by L. Ray Crittendon, Phillip Haskell, Ellis Hailston and G.E. Pinckney.
This classic shotgun has been made in many variations by the factory, including marine, tactical, and waterfowl and upland game version. It is easily the most popular shotgun sold, as measured by total numbers, with more than 10 million units sold.
The 870 has a robust cottage industry that is creating outstanding custom parts to enhance it one way or another.
There are many factory variations of the 870; one is Remington’s Police Model. It has been the standard-bearer of law enforcement shotguns since it was introduced and has seen service all over the world. The Remington Police Model is a bare-bones shotgun with an 18½-inch cylinder-bored barrel with 2¾- and 3-inch Magnum chambers, matte-blued or Parkerized finish, and a synthetic stock. The shotgun has beefier internal parts in the way of a forged extractor, a stronger sear spring and carrier latch spring. When I was the chief gunsmith for a DoD small-arms facility, we would heavily modify the Remington 870 for use as a breeching shotgun for various military units.
Remington produces many variations, but as with anything popular with consumers—whether it’s cars, motorcycles or firearms—once the consumer gets hold of it, there are any number of ways it can, and will, get modified. So, even though Remington makes the Police Model, many civilians will use that model as a base gun to build their unique tactical or competition shotgun. The 870 has a robust cottage industry that is creating outstanding custom parts to enhance it one way or another.
Deciding Which Mods Are Right for You
If you look at the shotgun section of the current Brownells catalog, you will see that there is no shortage of parts and accessories to modify this iconic shotgun, and some of the mods are extremely popular. The question is, Which the mods are most useful to you?
The answer will vary based on the specific needs of the individual shooter—who needs to ask themselves some questions.
Am I, or will someone else, be using this gun that is recoil-sensitive? What am I going to use it for—home defense, competition or both? What is my budget? And finally, Which modifications do I need to have, as opposed to what I would like to have?
For the 870 in this article, I started with a basic Police Model straight from the factory. This gun would start out as a Project Gun for my upcoming book on custom gunsmithing, so I was going to throw everything on to it plus the kitchen sink. I also wanted to use this gun as a home-defense shotgun, probably loaded with #2 birdshot—a good load for very close-range indoor use. The gun would also be used as a 3-Gun competition shotgun in the Heavy Metal Division, where only 12-gauge pump shotguns with iron sights are allowed.
When installing or replacing the trigger, sear or any fire-control components of any firearm, always perform a safety and function check with dummy ammunition prior to going to the range and firing live ammunition. Even small modifications such as polishing internal parts could create an unsafe condition and/or a serious injury. If you are unsure of the work you have performed on your gun, always have the gun checked out by a competent gunsmith for safety and proper functioning before firing live ammunition.
Without further ado, here are the top five modifications I chose for the Remington M870 shotgun, in no particular order.
Sights. Many people are under the impression that a shotgun is like a hand grenade: more of an area-type weapon than a precision firearm such as a rifle or even a pistol. They think of it as a point-somewhere-in-the-general-direction-and-shoot type of weapon, when, in fact, the shotgun is capable of great precision. This is true, especially with the right loads and if the shooter has the right training (as the late, great firearms trainer, Louis Awerbuck, demonstrated).
To aid in that precision, I chose a set of ghost ring sights with tritium inserts from Scattergun Technologies. The rear sight is drilled and tapped into the receiver; as a result, it should be professionally installed. They are rugged and highly visible and can be zeroed with specific slug loads.
Recoil Reduction. This is actually a combination of several modifications, and you can pick and choose which ones to install based on your budget and needs. However, I combined these into one category.
The first mod I added to the shotgun was to have the barrel ported. When you’re talking about barrel porting, there’s only one company: Mag-na-Port. The series of holes machined into the barrel redirects the expanding gas upward and rearward. Due to Newton’s Third Law of Motion, these holes force the barrel forward and down, greatly reducing the recoil. It’s a process that has been around for decades.
The second mod was to lengthen the forcing cone of the barrel, easing the transition of the shot column going from the shell into the barrel. It’s a common modification that competitive trap and skeet shotgunners have performed for decades.
Another recoil reducer is a Kick-Eez recoil pad, which is also popular with shotgun competitors. These are shooters who fire tens of thousands of shotgun rounds a year.
Finally, I added a muzzle brake/breeching device. This performs two functions: In conjunction with lock-busting ammunition, the breecher works as a stand-off device to destroy door locks, hinges and deadbolts when a tactical team is entering a structure. The stand-off device also has muzzle brake ports machined into it to redirect gas sideways.
Together, all these features make for a very, very soft-recoiling 12-gauge pump shotgun.
Custom Stock. There are many types and makers of stocks for the Remington 870 shotgun. The options include wood and synthetic, and manufacturers include Bill Davis, Hogue, BlackHawk! and Magpul.
One of the main advantages of using a custom stock over a factory unit is the greatly improved ergonomics. This means the stock will fit better, the shooter can control the recoil better, and the shotgun will not be as abusive to the shooter as a factory stock can be.
If the stock can be custom configured for adjustable length of pull and raised cheek pieces—as can the Blackhawk! and Magpul—the felt recoil to the shooter will be much less, and subsequent follow-up shots will be quicker and easier.
I chose the Magpul SGA buttstock, which features a raised cheekpiece and a spacer-adjustable length of pull. It was very easy to fit the Kick-Eez pad to the stock, and it looks great, to boot!
Extended Magazine Tube. Adding a mag tube extension is a modification many shooters would put at the top of any shotgun list (more rounds on tap are always a good thing), and I would have a hard time arguing. When installing the extended tube to the Remington 870, the magazine limiters (indentations in the tube) need to be removed. The tactical model I started this project with comes standard with either a five- or seven-shot magazine tube.
There are several ways to remove the indentations. One way is to just drill them out, but I don’t like this method for two reasons. For one, it is an amateurish way to do it and looks like hell. Two, there is always the chance the rim of the shotgun shell could catch on the opening of the hole. Admittedly, this is a very small chance, but it is a chance, nonetheless.
Adding a mag tube extension is a modification many shooters would put at the top of any shotgun list (more rounds on tap are always a good thing), and I would have a hard time arguing.
The other way to remove the indentations is to purchase a magazine tube dent raiser that “irons out” the detent from Brownells. Once done, clean it out with a Dremel or Foredom tool, along with a sanding drum to make sure the detent is completely removed. Function-test with dummy rounds first; then, head to the range to test with live ammunition.
Timney Sear and Trigger Job. This modification might or might not be high on everyone’s list. The factory trigger is fine for a combat shotgun, but for precise shooting with slugs, a quality trigger is hard to beat. The Timney unit is easy to install and comes with three sear springs: soft, medium and heavy. I chose the medium sear spring. And with a little additional polishing on the internal parts, the addition of the Timney trigger gave me a nice, crisp, quality 3-pound trigger with no creep and very little overtravel.
Honorable Mention—Tac Light. I went back and forth between the sling and the SureFire tactical light. In the end, the tac light won out. As useful as a sling is, the tactical light gives the shotgun day/night capabilities, and the SureFire 6v light—with permanent on/off and a momentary pressure switch—gives the gun much more flexibility.
As with any custom gun, the modifications I chose might not line up exactly with everyone’s idea of a “perfect” custom gun, and my top five mods might not be everyone’s cup of tea. But with the modifications I made, this Model 870 would be right at home as a near-perfect civilian defensive shotgun, as well as ideal for tactical use.
Editor’s note: A version of this article first appeared in the August 2017 print issue of Gun World Magazine.