Magazine Extensions for Remington 870

[Synchronizor]

It doesn't have the detent ball

If your barrel doesn't have a locking detent, the extension may work itself loose under recoil. Clamping it to the barrel should keep this from happening, but if you're going to clamp your extension, you might want to consider a 2-piece extension like the Nordic or Remington kits instead. These usually offer a better mate between the magazine and extension tubes, making for more reliable feeding.

Sorry this was less than prompt, the last time I posted in this thread was on a borrowed computer.

I watched a YouTube video on installing the extension tube. It said you had to dremel the stock plug stops so the shells won't hang up on them. Is this necessary. If so it seems I would be unable to go back to the stock configuration of I wanted to go hunting. Can anyone shed some light on this for me? Thanks.

You do have to remove the dimples to install a magazine extension, but that won't in any way prevent you from switching back to a magazine cap when desired. The spring retainer that locks into those dimples is an optional part that can be replaced with a press-in retainer or a magazine follower (see this video), or left out completely with the right type of magazine cap.

Brownells sells a detent tool which allows you to push the detents flush with the barrel allowing no hang ups and you can push in your detents if need them back

You can just drill the dimples out instead of blowing $83 (plus shipping) on a tool you'll only use once. Also, if you don't know exactly what you're doing, it's easy to FUBAR your magazine tube and/or receiver with the method shown in that video. Once you remove the dimples, there's really no good reason to try to put them back.

[TexasArmor84]

Does your 870 use a plastic spring retainer and an internal-ratchet magazine cap, or does it have a locking detent in the barrel guide ring? If the barrel doesn't have a detent in the guide ring, an unclamped extension may work its way loose under recoil. I have a WC +1 extension, and I have to keep tightening it when I use it with my barrel that doesn't have a detent.

Synchronizor I did some research on the wilson combat +2 extension on the wilson combat website they sell the kit and comes with a wave washer to use if you do not have a detent ball. This will keep it from coming loose. You can also purchase the wave washer by it self.

[Synchronizor]

I know the extension comes with a wave washer, but I've read reviews where people used the washer and still had the extension work loose during extended shooting. A wave washer is a lot better than nothing, but it isn't as positive a retention system as a guide ring detent or an extension clamp. Given time, the extension can still potentially work itself loose.

It's one of those YMMV things. For the type of shooter who blows through hundreds of shells in an afternoon, the washer may not be enough. For someone who only shoots a box or two at a time, the washer will likely be enough to keep things together. It could hold for a thousand shells, or the extension could come loose after a dozen shots. It's hard to say, but the possibility of it coming loose is worth mentioning.

I should have mentioned the wave washer though, so thanks for bringing it up. It is cool of WC to include one, and it should help.

[rowdyroutson]

The ATI fluted breacher extension is awesome imo. The spring seemed a little chinzy so I kept the one from my Wilson combat extension. I like it because it lines up perfectly with my barrel which is a little under 18.5 inches.

[RomeoPapa]

I believe Mesa makes the wave washers that Wilson supplies with their extensions. When I put on an extension, or even a magazine cap, I use a wave washer. But then I have some soft jaws for a pair of channel-locks,and I tighten the pee out of them. I've shot 300+ rounds at a time and never had one loosen up.

[Junkman192]

Hey guys, just bought an 870 tactical with the 5 shot tube. Anyone got a recommendation on what extension I should use? Never had to accessorize a shotgun, always just used them out of the box. Thanks!

[TexasArmor84]

I've just installed a Wilson combat +2 and work perfect and looks good only $45 on there site really works well for the price and quality can't beat it.

[Synchronizor]

Hey guys, just bought an 870 tactical with the 5 shot tube. Anyone got a recommendation on what extension I should use? Never had to accessorize a shotgun, always just used them out of the box. Thanks!

The Wilson extensions are a good bang for the buck, and don't need to be clamped since they're single-piece extensions (though it still wouldn't be a bad idea to clamp +2 or longer extensions if this is going to be a serious defensive gun). If you want something modular, two-piece extensions like the Remington or Nordic kits are more flexible since you can change just the tube to get various capacities. Nordic extensions are aluminum, while the Remington ones are steel, and have an end cap that accepts M16 bayonets if you also install a bayonet lug (not terribly useful, but pretty cool).

[Junkman192]

What's the difference between a one and two piece extension? Thanks for answering all these questions, like I said, new to all this!

[Synchronizor]

A single-piece extension consists of one solid part that screws on just like an elongated magazine cap. They're simple, easy to install and remove, and don't normally need to be clamped to the barrel to stay in place (though a reinforcing clamp can still be used to strengthen the extension in rough-duty roles).

A two-piece extension consists of a separate coupling and extension tube. The coupling is a common part that screws on like a magazine cap, and then an extension tube of the desired length threads into the coupling. Two-piece extensions are great if you want to have multiple extensions, since buying different extension tubes by themselves is a lot cheaper than buying the same number of complete extensions. The system also allows for a more seamless transition between the magazine tube and the extension tube, though you can experience feed hang-ups if you don't install the extension correctly. These extensions usually need to be clamped to keep the extension tube from backing out of the coupling, so they're a little more involved to install or remove, but the clamp and joint makes them more resistant to damage from impacts, and a lot of folks end up using a clamp-type mount to install a light or sling swivel anyway.

Here's a piece of my takedown & reassembly video demonstrating the installation of a magazine cap and both types of extensions.