Remington 870 Mag Extender Question

[NY27]

I have a Remington 870 Express Super Magnum 12 Ga. It holds 4 in the magazine. I purchased an Advanced Technology magazine extender. I unscrewed the cap at the end of the forend figuring that it would be easy to get the old spring out and put the new one in.

There is another cap underneath with a slot in it that I am not quite sure how to remove.

Perhaps someone could talk me through the process. Thanks in advance, I'm sure that someone will be able to help me.

[DefensiveCarry.com]

[Bud White]

On my 870 you remove the first came and then the second one you carefully pry out and unleash the 20 foot long spring from hell..

Not sure if the express is the same as the Std 870 but don't see why it wouldn't be

[SIXTO]

Yeah, its the same. Its a little easier to get at if you slide the barrel off too.

[Rob72]

Its easier if you get (IIRC) a 1/2"or 3/8" bolt, and run it into the hole in the spring cap, then work it out gently. Do wear glasses/safety goggles, if you haven't had a mag tube spring out, before. Really not a big deal, but they can "leave a mark" if you aren't expecting it.

Forgot to add: the 3-4" bolt keeps the spring from jumping out the side.

[P95Carry]

That seems to have covered it. The springs are not actually that strong but yeah - they are long

Added ext'n to mine without too much grief. Not shown in the pic is bracing clamp I fitted later - which nicely secures end of extension to barrel. Without it a sharp knock could cause problems.

Good luck with yours - let us know if all goes well.

[MoMike]

Just use a finger, push this cap down, and give it a quarter turn to the left. Then ease it back out.

[Superhouse 15]

Is it a solid, plastic cap with serrations around the edge? If it has a slot in the middle, it's a bit different than described. You must push it into the magazine and turn it to remove, IIRC. Use a flat-head screwdriver. Check to see if there are small dents in the side of the magazine, if so, it takes a little bit of work to fit the extended magazine, you must remove these little detents so the follower will pass. There should be groves in the serrated plastic plug that must pass these detents, thus the need to turn it. If you have a flat piece of stamped steel with a round hole in it, pry gently or run a bolt through it and pull it out like was posted above. Wear your goggles!

[rocky]

superhouse is right on. the small indents need to be filed down for shells to be able to pass to the extended mag. I found a dremel worked well, just take a bit of time.

[NY27]

Thanks for all the responses. I have been really busy between OT at work and getting oral surgery. When I get some free time I will give it an attempt. I'll let everyone know how it goes.

[Scot Van]

I have a Remington 870 Express Super Magnum 12 Ga. It holds 4 in the magazine. I purchased an Advanced Technology magazine extender. I unscrewed the cap at the end of the forend figuring that it would be easy to get the old spring out and put the new one in.

There is another cap underneath with a slot in it that I am not quite sure how to remove.

Perhaps someone could talk me through the process. Thanks in advance, I'm sure that someone will be able to help me.

Since I work for Advanced Technology, I'm probably the most qualified to help you out. Gimme' a call at my desk and I'd be happy to talk you through any install. Toll free
866-472-8590, however, MoMike has the right idea. You should NOT need to use your Dremel.

[SubNine]

I added a mag extension to my 870 Express Magnum. It had the little dimples in the mag tube. At first I was afraid to attempt it, but thought I'd give it a shot. My shotgun now holds 6+1 rounds!

[P95Carry]

Just to show mine closer up, quick pic, and with the addition of the bracing clip.

I bought the ext'n from another guy used so forget its origin right now, and maybe dr_cmg can remind me of the source where I got the bracing clip - also forgotten for now! Does reduce the vulnerability of the extra mag length.

[Scot Van]

I added a mag extension to my 870 Express Magnum. It had the little dimples in the mag tube. At first I was afraid to attempt it, but thought I'd give it a shot. My shotgun now holds 6+1 rounds!

Unless I miss my guess, that is the Knoxx stock w/ the suppression system in it, right, Spydey? How do you like it? I've had more than a few officers tell me that they've had some issues w/ short stroking the gun because of all the movement in the stock. Has that ever been an issue for you, on duty or at the range?

Some departments recommend racking the buttstock on the ground while holding the forend to clear the jam, but that not only seems rough on the gun, it isn't safe. Obviously, transitioning to sidearm is the common solution, but it is a shame to elimate the primary weapon if you don't have to. Any accessory that makes problems more likely can be a hazard, and definitely NOT for duty carry (which might be why Knoxx started offering this stock without the internal spring assembly).

Just wondering...

[SubNine]

I have no problems with my Knoxx Spec Ops stock. It's one of the best shotgun stocks on the market for reducing felt recoil, although I'm in no way recoil shy. I just hate waking up the next day with a sore shoulder.

[dr_cmg]

I bought the ext'n from another guy used so forget its origin right now, and maybe dr_cmg can remind me of the source where I got the bracing clip - also forgotten for now! Does reduce the vulnerability of the extra mag length.

Chris, your wish is my command. TAC STAR BARREL MAGAZINE CLAMP 12GA MOSSBERG, REMINGTON, WINCHESTER