One of the hottest guns for bolt-on accessorizing is the Remington Model 870 pump action shotgun. This shotgun has long enjoyed a reputation for rugged dependability and blue-collar affordability. Turning the 870 into a “tactical” shotgun for home defense and fast paced target shooting is a great hobby gunsmithing project. Actually, it’s several small projects as the options are just about limitless.

One of the most popular projects is to add an extended magazine for more ammo capacity. Choate Machine & Tool Company makes a lot of 870 accessories, including a variety of magazine extensions that are easy to install.

Remove the magazine cap and the magazine spring retainer. Remove the magazine spring and follower as well as the barrel. Newer model 870 shotguns will have two opposing detents or “dents” in the magazine tube designed to keep the magazine spring retainer in place, and these must be removed. The directions said to use a 3/16 inch drill, but that didn’t clean them up well enough, so I moved up to a 7/32 drill. There will be burrs and perhaps some of the detent left inside. Use a half round file, or better yet, a Dremel hand grinder with a rounded stone to clean them up until the magazine follower passes through easily. Finish with a Cratex bullet-point tip in the Dremel tool to polish out the grinding marks. Fit the magazine spring over the stem of the magazine follower and install it in the tube, making sure it can slide easily the entire length of the magazine. Replace the barrel. Compress the spring with your fingers as you work it down into the magazine tube until you can slip the magazine extension over the spring and fit it to the top of the magazine. Carefully screw it down tight. Fit the support bracket to clamp the front of the magazine to the barrel and you now have a high capacity 870 shotgun.

Most tactical guns will use a shorter barrel. I switched the 28-inch barrel on my gun for a 20-inch barrel with sights. Then I upgraded the sights. I removed the factory sights and fitted the gun with XS Sight Systems 24/7 Standard Dot Express Set. The front sight is a large white bead with a tritium glow-in-the-dark center. Installing it was simple. With the supplied plastic punch and a small hammer, drive the old sight out of the dovetail, left to right. It’s easier if you clamp the barrel in a soft-jaw vise. Then, reverse the direction to install the new sight. Mine was a very tight fit, so I made two soft passes with a parallel side, dovetail safe-file to open the sight ramp’s dovetail slightly before installing the new front sight.

If your 870 has fiber optic sights it is necessary to replace the sight base. Loosen the clamping screw on the rear sight and slide it off the dovetail. Install the new base by reversing the process and then install the XS blade with the single screw. The rear sight has a shallow V with a center, white, glow-in-the-dark line to lead your eye to the bead. Remember to tighten the locking screw very tight. I did not and my sight came off while shooting and fell into high grass where I could not find it.

Another alternative is to add an optical sight. I used a Remington saddle style scope mount. This is easy to install. Simply knock out the trigger retaining pins from the receiver, then slide the mount over the receiver until the holes line up. Now install the two supplied screws through the receiver and tighten them into the threaded side of the mount. Any optical sight can now be fitted using “Weaver” style rings. I installed the new Aimpoint Micro T-1 PO49 sight. This compact red-dot sight is light, small and very fast to use.

Almost every 870 makeover will include changing the stock and forend. The options here are almost limitless and I can only comment on those I have experience with personally. I have used both the Choate Mark 5 Stock and the Knoxx recoil reducing adjustable stock. Both of these pistol grip stocks are great. The Choate is a bit more comfortable to shoot with, but I also like the adjustable length of the Knoxx and the spring loaded recoil reduction. These are a simple bolt-on change. Remove the recoil pad on the old stock with a Philips screwdriver and reach inside with a flat screwdriver to remove the stock screw. Place the new stock on the receiver and tighten the supplied screw. The screw in the Knoxx stock is easier to work if you use the long hex screwdriver available from Knoxx. Of course, these are but two of the multitude of options for replacement buttstocks.

The forend is removed by removing the magazine cap or extension and the barrel and then using a special spanner wrench (supplied by with most replacements) to remove the forend retaining nut. Slide the forend off and install the new one by reversing the order.

Again, the possibilities are almost limitless. Choate offers a forend with a picatinny rail to mount accessories. This rail can mount on either side or on the bottom. Surefire has an excellent forend with a built in high-intensity flashlight. There is an on-off switch on the left side and a bar on the right that turns the light on when it is squeezed and off when it’s released, a great accessory for a home defense shotgun.

I added a Scattergun Technologies oversize safety. Remove the trigger group by pushing out the two pins in the receiver and then working the trigger free. Above the safety is a drilled hole with a pin through the top. Carefully push out the pin and catch the spring and ball. Slide the safety out of the trigger guard and replace it with the new safety. Replace the ball and spring. Push the spring down with a small screwdriver until you can re-insert the retaining spring. Install the trigger group back into the receiver.

Wolff offers replacement springs for the hammer and firing pin return which will insure more positive functioning. However, I don’t have enough room to cover their instillation in this segment.

My 870 is no longer a boring pump shotgun sitting unused in the gun vault, but it is the life of the shooting party. It’s also my “go-to” home defense long gun.