Since I began this series, I’ve received
a lot of requests for a video on take-down and reassembly of a Remington 870. This isn’t
something I had initially planned to cover; the 870 is a pretty simple design, and basic
instructions are readily available. However, the brief written instructions in
the owner’s manual leave much to be desired. And while there are a lot of how-to videos
and other online guides already out there, even the better ones I’ve come across only
show the process for one type of 870. So, I felt I could contribute by creating
a more exhaustive disassembly guide that would explain and demonstrate each step in greater
detail, cover all standard 870 models and configurations, give accurate part names,
and help new owners avoid the common mistakes and hang-ups that most people figure out the
hard way. Of course, all that detail and inclusiveness
doesn’t exactly make for a brief video, but don’t let the runtime scare you off.
I’ve added DVD-style forward and back buttons down here in the corners. If you have annotations
turned on, you can use the back button to replay previous steps; and the forward button
to skip past steps that you don’t need help with, or that don’t apply to you.
In addition, there’s a video outline in the description with clickable timecodes for
each step, so you can see at a glance how this video is organized, and jump directly
to a particular step at any point. Alright, let’s get started.
As always, the first step is a safety check. Make sure the gun is on safe, and the chamber
and magazine are empty. When I'm doing a complete take-down, the trigger
plate assembly usually comes out first. It can be removed at pretty much any point in
the disassembly process, but I’ve found that having the trigger plate and shell carrier
out of the way makes other steps a little easier.
The trigger plate is held in by two trigger plate pins. Pushing these out is best done
with a thin screwdriver or punch, but anything sufficiently stiff and narrow will work in
a pinch. I’ve even used the stem of a Tootsie Pop before. But if you want a dedicated pin-pusher
tool, a cheap scratch awl like this will work just as well as a more-expensive “official
gunsmith tool”. You can remove your pins in either direction,
but the way these guns come from the factory, it’s easiest to push out the front pin from
right-to-left, and the rear pin from left-to-right. If you like, you can switch the front detent
spring over to allow both pins to be easily removed and reinstalled in the same direction.
See this video for details. Before removing the pins, close the action
to take any downward force off the trigger plate assembly.
Now, holding the receiver up off your work surface, place your tool in the center of
the pin and push it straight through and out. Put it somewhere where it won’t roll away
and get lost, then turn the gun over and repeat the process with the other pin.
If you’re having difficulty simply pushing a pin through, use one hand and arm to support
the gun and hold the tool in place, then gently but firmly tap the pin through with your other
hand. If you don’t think you’re that coordinated, you can also place an object under the gun
to support it, or sit down and lay the gun across your knees.
You shouldn’t need to hammer on the pins to get them out. These aren’t tight-fitting
friction parts, each pin is held in place by a single detent spring that engages one
of these notches. Moderate force or a couple light taps should be sufficient to disengage
the pins from their detents, and they’ll come the rest of the way out fairly easily.
Once both pins are out, grasp the back of the trigger guard, just below the safety button,
and with a little pull and a slight forward rotation, the trigger plate assembly should
slip right out. Some aftermarket furniture will enclose the
rear of the trigger plate, and must be loosened or removed to take out or replace the trigger
plate assembly. If you’re not sure how to do this with your specific stock or grip,
refer to the product’s instructions or contact the manufacturer.
A number of popular aftermarket accessories replace the trigger plate pins with their
own mounting fasteners, which should be self-explanatory. When the trigger plate assembly is out of
the gun, keep the safety engaged at all times so that you don’t accidentally pull the
trigger and allow the hammer to snap forward. It isn’t the end of the world if this happens,
but it’s not great for the trigger assembly parts, and it could be painful for you.
If you do want to release the hammer for cleaning or inspection, hold it down while you pull
the trigger, then let it up gently; and return it to the cocked position before putting it
back in the receiver. The next thing to come off is the magazine
cap or magazine extension. This is what holds the barrel in place.
If you have a magazine cap, simply screw it off counterclockwise. You should be able to
do this by hand, but if it’s too tight or you can’t get a good enough grip, use a
pair of channel-lock pliers to break it loose. To keep from chewing up the part, wrap it
with a rag or a scrap piece of leather, and make sure you have the pliers oriented correctly
so that they don’t slip. Now, even when empty, the magazine spring
will be under compression inside the tube, and it can launch a cap with impressive force.
870s without magazine extensions usually come from the factory with a magazine spring retainer
that holds the spring in the tube when the cap is removed, but this is an optional part
that not all owners opt to use. If there is a spring retainer, leave it in the tube for
now. If you want to take it out, it’ll be easier to do so later on.
If your gun doesn’t have a spring retainer, or you’re not sure if it has one or not,
hang onto your cap as you remove it. If your gun doesn’t have a spring retainer, go ahead
and pull out the magazine spring so it won’t be in the way.
Shotguns used for hunting may also have a magazine plug that limits the gun to a legally-mandated
capacity. These vary, but usually take the form of a slender rod that sits inside the
spring. If you have a magazine extension, any reinforcing
brackets or other tube-mount accessories need to be removed before the extension can come
off. To take off a factory magazine extension bracket,
use a flathead screwdriver to remove this screw, then slide it off the front of the
gun. If the bracket doesn’t slide freely once the screw is out, pull it open slightly
so it won’t scrape up the gun’s finish as it’s removed.
Aftermarket clamp-on accessories will vary. I won’t try to cover every possibility here,
but they’re not usually too tough to figure out. Again, refer to instructions or contact
the manufacturer if needed. Once everything’s off the extension, unscrew
and remove it just like a magazine cap. Again, the spring will be under compression even
if the magazine is unloaded, so hang on to it if you don’t want it to go flying across
the room. And with longer extensions, control the spring as it’s released so it doesn’t
tie itself in knots. With the magazine cap or extension removed,
place the fore-end in the middle of its travel so that the bolt will unlock, but the back
of the fore-end won’t get in the way; then slide the barrel straight out of the receiver
and off the magazine tube. With some specialty slug hunting 870s, the
barrel can be pinned directly to the receiver with a single screw. If present, this screw
must be removed before the barrel will come off.
Some 870 barrels come with removable, interchangeable choke tubes, or other choke-mounted accessories
like the breaching stand-offs on some tactical models. You can easily figure out if you have
a removable choke by looking at the muzzle. Removable choke tubes simply screw out of
the barrel. Flush-fit tubes and some extended ones have notches in the end to accept a specialized
choke wrench or key, but an appropriately-sized flat object like a coin will work too. Many
extended choke tubes can simply be removed by hand.
A choke tube may take a bit of torque to break loose, but then, it should thread out easily
if it’s in good condition. If a tube refuses to move, the threads may be rusted, damaged,
or otherwise frozen up. If you suspect this to be the case, and you’re not sure how
to deal with a locked-up choke tube, take the barrel to a gunsmith or other experienced
individual. Trying to force it out may just make things worse.
With the tube removed, the end of the barrel is very thin and easy to damage, so be gentle
with it, and NEVER fire the gun without a choke tube installed. For more information
on caring for choke tubes, see this video. With the barrel off the gun, the fore-end
assembly and the rest of the action come out together, but the left shell latch has to
be held down to let the action bar by. When I do this, I hold the fore-end in one
hand and the receiver in the other. Using a thumb or finger, I’ll reach through the
bottom of the receiver and depress the shell latch. With the other hand, I’ll slide the
fore-end assembly and bolt components forward out of the receiver and off the end of the
magazine tube. If you’re depressing the left shell latch
properly, these components should slide out very easily, so if something hangs up, don’t
force it. Check the bottom front corner of the ejection
port. The slide assembly can shift up out of its notches in the action bar and catch
right here if you’re not holding the gun upright, or inadvertently pushing up on the
slide assembly. Make sure the slide assembly is sitting down in the action bar, and it
should come out unhindered. Once they’re out of the receiver, the breech
bolt and slide assemblies can be lifted off the action bars.
Now, the only remaining step is to remove the spring retainer if your gun has one - and
you want to remove it. Normally you can leave this where it is if you’re just changing
barrels or cleaning the action, but if you want to pull your magazine apart during
a full take-down, it’s less of a hassle with the barrel and fore-end assembly out
of the way. There are two types of spring retainers. The
old-style retainers are sheet-metal parts; while new-style spring retainers are plastic,
and have teeth molded into the front end that help to keep the magazine cap from backing
off. The older-style spring retainers are held
in the magazine tube by friction alone, and you’ll need an appropriate tool to pry one
out. Any slender, stiff object that will provide the proper leverage like a screwdriver, Allen
wrench, or even a long nail will work. I just use my trigger plate pin tool.
When prying out a metal retainer, never work your tool directly against the edge of the
magazine tube. This can permanently damage the tube or its threads. Instead, insert your
tool into the hole in the center of the retainer, and use the retainer itself as a fulcrum,
moving the tool around to work it out of the tube bit by bit.
Also, remember that there’s a compressed spring inside the tube, so be ready to catch
the retainer as it comes out, and don’t point it at your face.
The newer-style plastic spring retainers are much less of a headache to take out. These
are held in the magazine tube by a pair of partial-length slots that engage two dimples
stamped in the end of the tube. To remove one of these, insert a flathead
screwdriver into this slot. Then, simply push the retainer back into the tube and past the
dimples, give it a quarter-turn to line up the dimples with the full-length slots, and
let the magazine spring push it past the dimples and out of the tube.
This can also be done without tools, just a finger, but it’s easier to use a screwdriver
if you have one handy. If you want to remove the magazine follower,
hold the receiver at a downward angle, and it should slide out, though you may have to
give it a little push to get it going. If your magazine tube has the dimples in the
end, you’ll need to line up the two slots in the follower with the dimples to get it
out of the end of the tube. If the follower gets stuck for some reason,
you can insert your magazine spring into the tube from the receiver end and push it out.
And that’s a basic disassembly of a Remington 870. At this point you can see just how simple
these guns really are to work with. I have some other videos planned showing how
to take the gun apart further - I’ll leave annotations here when I get around to them
- but this is as far as you should have to go for normal cleaning, maintenance, and configuration.
Now for reassembly. For the most part, the gun goes back together
the same way it came apart; but there are some differences, and a few more tips I’d
like to share. As with disassembly, If you’re using a spring
retainer, it’s usually less of a hassle to assemble the magazine while the receiver
is stripped. First, insert the follower, spring, and magazine
plug if desired. Installation of a new-style plastic spring
retainer is simply the opposite of removal. Place the retainer over the end of the magazine
spring, and insert it into the magazine, lining up the full-length slots with the dimples.
Then, using a finger or screwdriver, push it past the dimples, give it a quarter-turn,
and let it back up. When installed correctly, the retainer will
stick out of the end of the magazine tube about a quarter-inch, and won’t be able
to rotate very much in place. Once again, the older-style metal spring retainers
are more of a hassle. To get the retainer started in the tube, insert
the side opposite the slot first, then squeeze the two halves of the retainer together and
work the other side in. Don’t be namby-pamby with this, it will take a fair bit of force
to compress the retainer and get it into the tube.
Once you manage to get it started, push it further in so that it won’t pop back out
or get in the way when reinstalling the cap. The manual will tell you to tap the retainer
in until it’s flush with the end of the tube; but it’s way too easy to damage the
end of the tube by hammering on the retainer. Instead, press it most of the way in with
your thumb or palm. Don’t worry too much about pressing it in to an exact point, just
get it in far enough for the magazine cap to engage the threads. If the retainer needs
to be deeper than this, it’ll get pushed down when you tighten the magazine cap.
Now once again, it doesn’t really matter when you install the trigger plate assembly,
but I’ve found that it’s easier to insert and line up when the action bars and slide
aren’t in the way. Before reinstalling the trigger plate assembly,
give it a once-over to ensure that everything’s as it should be.
The safety should be engaged, and the hammer should be cocked.
The sear spring should be in place between the connectors and the sear.
The carrier dog should be centered over the carrier dog follower; and the carrier dog
and carrier should both move freely. The rear finger of the action bar lock needs
to be underneath the left connector, and it should push the connector up when the slide
release is pressed. Finally, the carrier pivot tube and the trigger
plate pin bushing should be centered in the assembly, and each should have a detent spring
in one end. Once the trigger plate assembly is ready to
go in, insert it carrier first into the receiver, and align the front tube and rear bushing
with their respective pin holes. Then, insert the trigger plate pins.
As with disassembly, you can insert the pins from either side, but if your detent springs
are in their factory locations, it's easiest to insert the rear pin from the right, and
the front pin from the left. Push them in until they engage the detent
springs and sit flush with the sides of the receiver.
They should click into place without excessive force, but you can give the pins a few light
taps with a non-marring object if you need to.
If you can’t insert a pin all the way, check to make sure your trigger plate assembly is
properly lined up with the pin holes. If it’s your front pin giving you trouble, you may
have a displaced shell latch. See this video for more information.
Next, make sure the shell carrier is in the down position, then slide the fore-end assembly
onto the magazine tube. Set the slide assembly on the action bars, place the breech bolt
assembly on top of that, then line them up and insert everything into the slots in the
receiver until they stop. This time, both shell latches come into play.
First, hold down the right shell latch and bring the slide back until it stops again.
Then, release the right shell latch and depress the left one, and bring the fore-end back
the rest of the way. If you removed the choke, put some oil or
grease on the tube’s threads if they’re dry, then screw it back into the barrel and
snug it down firmly. Don’t reef on it if you’re using a choke wrench; repeated over-tightening
can severely damage a barrel or choke tube. Before reinstalling the barrel, check the
bore to make sure you didn’t accidentally leave a cleaning patch or some other foreign
object in there. To reinstall the barrel, put the fore-end
in the middle position, then insert the rear of the barrel into the receiver, and slide
the guide ring over the magazine tube. Before you try to seat the barrel, look through the
ejection port and make sure this cut in the rear of the barrel is lined up with the ejector.
The ejector is not an especially fragile or breakage-prone part, but it’s not intended
to stand up to a ham-fisted owner slamming a barrel against the tip. If this breaks,
the gun will be out of action until you or your gunsmith orders and installs a replacement.
Just take an extra half-second to line things up properly, and you shouldn’t have any
issues. Now, without letting the barrel fall off – standing
the gun on its butt end is a good way to do this – reinstall your magazine cap or extension.
If you’re using a cap, simply insert your follower, spring, and any other components
into the magazine tube – if they’re not already held in place with a spring retainer
– then tighten the cap against the barrel guide ring. A firm hand-tightening should
be sufficient, no need to crank on it with any tools.
If you’re using a single-piece magazine extension, you can install it just like a
magazine cap. But if your extension is the type with a separate tube and coupling – like
the factory Remington extensions – the coupling has to be installed by itself first. Once
it’s completely tightened against the barrel guide ring, insert the follower, spring, and
so on; then place the extension tube over the spring, and thread it into the coupling.
Tighten it down firmly, making sure not to leave a gap between the tube sections.
If you’re using a factory extension bracket, slide it over the barrel and extension; again,
bending it open if needed. Line up the bracket’s screw hole with the groove in the extension
tube, then replace and tighten the screw. And with that, the gun’s back together.
Point it in a safe direction and give it a function check; either a basic rack & dry-fire,
or by running some snap caps or dummy shells through it.
As always, I encourage any and all questions. Firearms are complex pieces of equipment,
so if you’re not sure what you’re doing, consult your manual, ask questions, or get
assistance. I’m also open to constructive feedback,
and topic suggestions for future videos. As I mentioned at the start, this video wasn’t
something I was planning to create until folks started asking for it. If there’s another
topic you’d like to see me cover, go ahead and let me know.
Until next time, please stay safe, have fun, represent the shooting community in a positive
light, and encourage others to do the same.
