Shotguns are powerful and versatile weapons but they have very limited magazine capacity. That is why this is one of the first things for a shotgun owner to improve when he starts building his tactical / home defense Remington 870 shotgun.

We can extend shotgun magazine capacity/bearing amount using several methods:

1. Install magazine extension (1, 2, 3, 4+ rounds)

Remington 870 Magazine Extension by Choate Tool Co
Remington 870 Magazine Extension by Choate Tool Co

2. Add  ammo cheek pad (carrier) to stock (usually holds 5-8 rounds)

3. Install side-saddle on receiver (holds 4, 6, 8 rounds)

Remington 870 4-Round Side Saddle by TacStar
Remington 870 4-Round Side Saddle by TacStar

4. Add shotgun sling with bandolier (shell holder).

Each method has its own advantages and disadvantages. I will have posts about each method later but today I want to describe the first one: how to install magazine extension on a Remington 870 shotgun.

There are many different extensions on the market today:

1. TacStar Magazine Extension
2. Choate Magazine Extension
3. Nordic Components Magazine Tube Extension
4. Original Remington Magazine Extension
5. Scattergun Technology Magazine Extension
6. Vang Comp Systems Magazine Extension

Attention: Manufacturers of extensions consider that the standard capacity of the Remington 870 Express shotgun is 5 rounds (4+1), that is why when you want to buy magazine extension for 2 rounds, you need to choose the 7-shot magazine extension.

Instructions on installation of the magazine extension on Remington 870 Express

If you have standard 4+1 Remington 870 Express shotgun (or even the one with factory +2 extension) the process will be longer than on Remington 870 Police which doesn’t have dimples in magazine tube. Remington 870 Police shotguns with previously installed magazine extensions do not have “dimples” in magazine tube and will readily accept any magazine extension.

Sometimes there are no dimples on older Remington 870 shotguns.

Remington 870 Express with 4+1 capacity has two dimples in magazine tube. You need to remove them for follower to go through.

There are two known methods to remove them:

1. Drill them out using dremel tool
Drill out the dimples. You will have two small holes in magazine tube.
2. Socket method using 16-17mm socket.
Hammering the socket inserted in magazine tube to press out the dimples.

Removing Dimples in Magazine Tube Using Hammer and Socket
Removing Dimples in Magazine Tube Using Hammer and Socket

I highly recommend to use the dremel method and to drill out the dimples in magazine tube. I have used both of them on my shotgun and think that diameter of the magazine tube became bigger because of the socket method. I had some problems installing magazine extensions and sling mount. Also, I’ve heard about the similar problem from another Remington 870 Express owner.

Also, I know that socket can stuck in your magazine tube, I’ve even heard that somebody couldn’t get it out of the magazine tube and ended up buying a new shotgun!

Recommended Products:
Remington 870 Magazine Extensions
Remington 870 Magazine Extensions
Get Remington 870 Magazine Extensions here:
Remington 870 Magazine Tube Dent Raiser
Remington 870 Magazine Tube Dent Raiser
Get Remington 870 Magazine Tube Dent Raiser here:

Related Post:
Magazine Extensions for Remington 870 Shotgun (Nordic Components, Choate, TacStar, Remington, ATI)


  1. I have used the “socket method” to remove the dimples on my Express. It works flawlessly. The dimples are in a steel tube. The best method for removing them is the same as any other metal working method (such as auto body work). There is no need to drill or file here. Simply work (GENTLY hammer) a lubricated hard object of similar diameter(such as pipe or socket) into the tube. Once in (it will be tight) simply use a metal working hammer (light weight) and GENTLY tap on the OUTSIDE of the tube (over dimples) until the “dimples” blend in with the rest of the tube. It’s easy, and basic metal working. You will then have a smooth mag tube, void of any holes or thin weak spots that need rebluing (“socket method”, done properly, will retain its finish).

  2. Bill Webb

    I respectfully disagree with the view to not use a socket to remove the dimples; I agree with Ken’s view. It takes very little effort to tap-in the correct size socket with a little oil on it–always leaving at least 1/2″ extended so it can be gently removed. If you are lucky enough to have a 1/2″ drive socket extension, you may find that works even better. When the socket is in place (and most of the dimples are thereby removed), GENTLY tap on the dimples with a SMALL hammer which results in a smooth surface, with no loss of metal and virtually no holes through the tube. As with Ken, I saw no damage to the finish. Start to finish time, 5-6 minutes. Grinding the dimples off or drilling them out is not necessary.

  3. I chickened out and took my 870 express to a gunsmith friend of mine.He used a modified socket method.He had a tapered steel rod held horizontally in a vice just a bit thinner than the magazine tube.He then slid the magazine tube onto the rod and using a small hammer gently knocked out the dimples.Although you can still see where the dimples were because of the marks made by Remington in the factory,when you run your finger around the inside of the tube you can’t feel a thing,smooth and flush to the magazine tube,no marking to the finish and all within five minutes.

  4. I have looked at both methods.. Does a low impact precision file and a little time.. sound good too anyone especialy the gun? Then maybe a little blueing. No holes no pounding smooth?

  5. Dwayne Harness

    Hi, just thought I ought to share a little trick to remove the stuck socket, if you are planning to use the socket method, (which does work if done properly),you need a couple more inexpensive item’s before you start.
    1. 1 1/4×6 inch carriage bolt
    2. 1/4-20 nut’s
    3. a 3/4 inch spark plug socket

    now assemble the expander as i call it, by putting the carriage bolt through the square end of the plug socket, them through the square end of the 16-17 mm socket, thread the nuts on the carriage bolt and tighten them together at the very end of the bolt threads. this leaves the two sockets loose so that after driving the socket in the mag. the plug socket can be used kinda like a dent puller or slide hammer to remove the smaller socket. also if you only drive the socket down a little at a time, and if you marked the approximate location of the dimples before you started, you can tap the outside of the mag. tube with a brass or nylon mallet, when the socket feels loose, drive it a little more, and repeat the tapping till the socket needs to be driven again. it will iron out the dimples without enlarging the diameter of the tube. the key to this method is go slow.

  6. I drilled mine. Use a bit about the size of the dent, and Follow up with a brake cylender hone. Works great

  7. I tried the socket method. worked horribly. Then I read about how it’s bad to send force down towards the stock. ended up drilling them dremelling smooth the tube. I did lose some finish though.

  8. It’s no the dimples that are the problem when using the socket method. That method does a great job of taking the dimples out alright but with all that hammering you are taking the chance of weakening or altogether fracturing the braze joint connecting your mag tube to the receiver.

  9. I used a socket, very easy. I was a little nervous about getting it stuck in the tube so I ran some para-cord through the socket and knotted it off just in case I knocked it to far down the tube and needed to pull it out. Fortunately that didn’t happen but I think the cord would have been more than enough to pull it back out.

  10. Is there a part number for the Forend Tube assembly used in the 870 Police model – Seems that would be the easiest, just replace the part with one without the dimples.

  11. I started to use the socket method. A 5/8″ socket pushed the dimples quite easily. When I moved to a 17mm socket, it wouldn’t come close to fitting in at all. I guess the outside diameter of my 17mm socket was just too big. I didn’t have any other sizes that came close.

    I switched to the dremmel and ground out only the inside of the dimples. After padding the tube and chucking it in a vise, I used a cylindrical stone to remove the material and make it flush, then followed with a grey soft polishing tip. Overall it worked very well. Also, I avoided creating holes in the tube.

    I also wadded up a paper towel and put it down the tube before I started working to keep dirrt from going down the tube. When done, I just used some needlenose pliers and pulled it out.

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