View Full Version : Home made mag extension for Remmy 870?

March 16, 2011, 11:01 PM
Hi Guys!
This is my first post, and I'm writing from my iPhone whos spelling suggestions are really crappy, still I'll try to keep it understandable...

I'm from Sweden, as most of you know the biggest nation in Scandinavia, about 1750 kilometers, that would be about 1100 miles from North to South.
I live in the extreme south, just a couple of miles from the south coast.
As you probably guessed firearm regulations are miles from those of th US.
You can get a gun, hunting is popular so all kind of hunting rifles is quite easy to buy. You need a hunting license that includes practical & theoreticall tests, but when that's done all you need to do is get a gun safe and choose your gun... (But when you've chosen the gun you can't bring it home, you have to register the gun via the police witch takes weeks...)
When it comes to handguns it's à different story, possible - yes but it takes 3-4 tests, recomendation etc...

But this was about shotguns. The important stuff could be singled down to this; hunting - totally accepted. Sport shooting (ie Trap & Skeet) - accepted.
Any othet use TOTALY unacceptable... ;-) Self defence? Dream on, if you should shoot and injur a burglar in your own home the chanse of YOU getting charged & convicted is really high... This might sound totally crazy (maybe because it is...), but there has been cases in Sweden where a home owner injuring a burglar have been found guilty of assault while the burglar has gone free because of lack of evidence... Crazy!!
Since hunting and trap/skeet are the only 'accepted' usage of shotguns the gun stores here don't have any 'tactical' products. If we want em' we have to order them from the US. Witch is hard since your State Department have strict rules. The result is that a stock or sling that you could by anywhere in the US for like 50 bucks costs like 200 bucks here - without shipping... ;-(

Another thing, since hunting & Trap/Skeet etc. are the only accepted activities including a shotgun, the magazine restriction (no of shells) that is 2+1 for all kinds of shotgun hunting, apply to all shotguns. It's legal to buy & own magazine extensions, but you can't hunt with it attatched and on the shooting range people would see you as a terrorist if you brought your 8 round shotgun... ;-)
Hence, you can't buy a magazine extension in a Swedish gunshop.

I own two shotguns, a over/under & Remmy 870 pump.
Now I'd like to 'pimp' my 870 into a 'tactical looking gun' but I don't Sanna spend 100:reds of dollars for parts that are cheap in the US.
So, I'm gonna make my own magazine extension!
What do you think of that? Can't be that hard!? A pipe of the right dimensions, some help to thread the tube and a 'nut' to keep the magazine and the extension together. Am I missing something or is it that easy!?
The extension tube does'nt need to be made from 'specially hardned steel - or?
A spring is easy to find an costs less than 15$. Do I need anything else?
Is this a good idea? I guess it would save me like 100-120$, so it's worth some job - I like building/modifying stuff so It would acctually be fun!!
So, give me some advice!!

March 17, 2011, 12:34 AM
Greetings Hurricane and welcome aboard.

Good luck with your project. The difficult part will be finding a tube with an appropriate diameter and wall thickness. High strength or heat treating will not be necessary. The rest of the project's success rests with your attention to detail and mechanical abilities.

March 17, 2011, 08:05 AM
Be sure the transition from factory tube to extension is smooth, otherwise, shells, follower, or spring might get caught on the edge.

I thought there was IPSC (http://ipsc.se/) shotgun in Sweden? Regardless, they may know how to get magazine extension tubes, although the good ones (http://shop.nordiccomp.com/NC-Shotgun-Extension-Complete-Assemblies-for-12ga-12GA-EXT.htm) are about US$80 over here.

Good luck


March 17, 2011, 08:48 AM
lmccrock your here too!!

the nordic 12Ga follower,, will make the tube work better it is longer and has 3 rings, that make the Mag tube transition better


March 20, 2011, 12:11 AM
I guess I was really tired when I wrote the first post...
It's not a Remmy 870 - it's a Winchester 1300 Turkey.
:confused: I talked to a guy about the Remmy just before I posted so... ;-)
How's the magazine in the Turkey version? It's the shortest, is 4 (+1) factory standard? Anyone got one? Would like to know hos long the magazine spring is in the 'standard' version?
I'll measure all dimensions of the mag tube, down to the millimeter, and then go to a metal shop and ask them to make the extension for me. They have some kind of computerized machine that could do almost everything...
So what I need to do is choose material and dimensions/size...
Will post images if it works out... ;-)

March 20, 2011, 12:57 PM
I looked up the Midway dealer for Sweden and saw how high the price is for the 2 round Tac Star extension for the Winchester 1300. $133 USD. OUCH! it is only $42 at MidwayUSA for a 2 round extension. They have a 5 rounder for not much more. http://www.midwayusa.com/viewproduct/?productnumber=582628

March 20, 2011, 02:02 PM
If you are thinking of making the extension out of a single piece of metal, I believe they are usually two pieces that some manufctgurers solder or weld together. One piece replaces the magazine cap and I call it the collar. The inner diameter of the collar is threaded so one end screws onto the magazine and the threaded end of the extension screws into the other end of the collar. If something is not done to keep the extension from unscrewing during use, it will unscrew and fall off the end of the magazine.

I believe some manufacturers solve the problem by soldering or weldilng the extension to the collar. Remington keeps it from unscrewing by using a clamp that fits on the barrel and the extension. When removed the extension breaks down into three pieces; the clamp, the collar, and the extension tube.

It is critical that the end of the extension fits flush against the end of the magazine when everything is mounted, else the sping or shells will catch in the crevice between the two.

March 20, 2011, 02:29 PM
Would a mag extension like this fall under ITAR?

March 20, 2011, 06:28 PM
I don't know about ITAR but would worry that some law was being violated if Midway won't directly ship.

March 20, 2011, 09:38 PM
Yea, I know 133$ and then you have to add handling & shipping plus fees/extra shipping costs for shipping outside US... It would be about 265-290$... How's that for overkill... ;-)
The thing is that Midway Sweden have the tubes, but some, US or Swedish, law's been changed. So at MidwaySweden you get this message 'In stock' and a 'OK' price, but! When you look closer like 85% of the stuff (and that's A LOT) are marked with some cryptic explanation, in super small letters, translating into something like 'We have it, and we sell it, but we have'nt got export/import approval yet, wait a week or so...' And it vad been like this for at least a year... And you can't find this stuff in Europe, thats crazy, this is Sweden, we always can buy what ever we want... ;-)
New expirience... ;-)

March 20, 2011, 09:47 PM
The tube:
I'm goin' for a pre-existing piece of tube of the right size.
Then I'll go to the metal shop and ask them to cut it to perfect length, add threads that makes a perfect fit so it could be attatched. I'll guess I'll ask them to thread both ends so that I can use the original cap. I'll add an extra clamp to secure it to the barrel. Sounds kinda' easy... ;-)
(I'm gonna get a new, long, magazine plug aswell since I don't want to break any laws or regulations...)

March 20, 2011, 11:20 PM
I am thinking you need something like a coupler used to joing pipes together. The outside of the magazine tube and the extension tube is the mail thread and the female thread is on the inside of the coupler.

March 21, 2011, 07:24 PM
Good point!
My description was kind of bad... One end will be threaded exactly like the magazine and the cap will screwed on to it. The other end will get a small piece of pipe with somewhat larger diameter attatched. This short piece of pipe will be threaded on the inside and, maybe, welded to the new extension. So the extension will be attatched the same way as the cap. Am I making sense?
Asked the guy at the shop for a price, he could'nt tell right now but he guessed about 100 SEK... Thats about 12-14$ including material and the job...
Sonds good to me!! ;-)

March 22, 2011, 07:28 PM
Any ideas or tips on how to 'repaint' the reciver, magazine tube & barrel?
Is Parkerizing the 'only way' or could spray painting / air brush give a good result?

March 22, 2011, 08:15 PM
Make sure that the inner diameter of the magazine and the magazine extension line up and fit flush to one another. Have you tried buying from any of the US online houses and is it legal for them to ship direct to you in Sweden?

March 23, 2011, 08:07 PM
Because of the price - no, I have not tried to order from the US.
From a Swedish point of view it's totally legal. From an American point of view it's legal if I buy from a registred dealer and the value is less than 100$.
But if I've got it right most US dealers don't like shipping to Europe since they have to do some kind of extra paperwork and they have to ship with UPS or FedEx. So most online shops don't ship outside continental US.
(And those who do add a shipping fee that ussually is like two-three times higher than the item it self...)

December 8, 2011, 04:23 PM
Hello there,i have made my own an 10 round 12g extension ,and its very easy,the tube you can find it everywhere,the diameter is 2.3-2.4cm internal and outside is 2.8-3 cm,then for the thread you can buy an extra magazine cap and drilled ,the with tig weld you can do a good finish touch,the difficult for me is to find the spring because is double in length ,and we dont have lot of stores that they supply them,if you have any suggestions for the spring ,i will be happy to hear from you,
Thanks alanios