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macbeau

Factory 8 rounder to 10 rounds.

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Part one

I have repeatedly seen requests here on how to turn a factory 8-round magazine into a 10-rounder. Hopefully, this is "sticky" worthy and will answer most (if not all) questions about the process.

 

Converting an 8-round mag to accept 10 rounds is a fairly simple process and can be done with simple tool. As a basic guide, you will need:

1. A factory Saiga .308 magazine.

2. A ruler or tape measure (calipers work great, if you have them)

3. Something to mark measurements with (pencil, nail, pick, etc)

4. A fine tooth saw (copeing or hack). A dremel can be used but not necessary.

5. A semi-coarse file.

6. A craft / hobby / utility knife.

7. Something to push the follower all the way to bottom (I used the handle of a cresent wrench here).

 

CIMG1224.jpg

First - magazine disassembly.

Locate the floor plate and find the square detent hole in the bottom.

CIMG1225.jpg

Using a nail or like-sized punch, depress the square detent about 1/8 of an inch. At the same time, gently slide the base plate toward the back of the mag body. These can be a bit tight on new magazines.

WARNING! DO NOT SLIDE IT ALL THE WAY OFF YET!

CIMG1226.jpg

Once you have the base plate about half way off, hold it with one thumb and use your other thumb to put pressure on the plate just below it. (These mags are wayyyyy over sprung and under considerable tension - even unloaded.)

CIMG1227.jpg

After you have positive pressure on the sub-plate, gently slide the base plate all the way off. After that, ease the sub-plate, spring and follower out of the mag body.

CIMG1228.jpg

 

Part two

Here is the factory follower.

CIMG1231.jpg

CIMG1232.jpg

It is 1.837" (inches) tall from top to bottom, as measured from the back of the follower.

CIMG1237.jpg

Also make note of the raised ridge / rail on the forward side of the follower. It rides in a corresponding track on the inside of the magazine body.

CIMG1238.jpg

CIMG1251.jpg

Measuring from the top of the "hump' on the top of the follower, measure down approximately 1.3" (inches). Scripe a SQUARE line forward and cut off the bottom of the follower with a fine tooth saw. Clean and square up the cut area with a semi-coarse file.

WARNING - Leave at least 1/8" - 3/16" (inch) of the track rail on the forward side of the follower! DO NOT REMOVE IT, FILE IT DOWN/OFF OR CUT IT TOO SHORT! It guides the follower up and down and helps keep the follower from "tipping" which will cause it to bind in the mag body.

CIMG1240.jpg

The battery on my clipers was going out (display flashing), but it ended up being 1.25" (inches) tall after cutting, filing and dressing.

Next - use the file and utility knife to create (scrape) a slight bevel / taper on both the inside and outside of the bottom edge of the follower. The will help keep the follower from binding in the body and help guide the spring up into the follower during compression (loading).

CIMG1252.jpg

CIMG1253.jpg

CIMG1255.jpg

 

part three

sub-plate and reassembly.

You will notice on the sub-plate that there are two upward protruding "legs". These will need to be trimmed down. The overall height on mine ended up being .85" (inches) after trimming.

CIMG1246.jpg

After making sure all burrs are removed and everything is nice and smooth and rounded on all of the parts that you worked on, reassemble the mag in reverse order as disassembly. I recommend using a dry silicone spray on the internal components to ease everything going back together and help reliability.

CIMG1249.jpg

Also - after final assembly, find something to compress the follower all the way to the bottom (not ammo). You may hear some mild crunching or popping. That is just the spring finding it's path to the under / inside of the follower (the taper / bevel you applied earlier should help with this). You should only need to do this once after reassembling the magazine.

CIMG1256.jpg

Now you should have a fully functional 10 magazine. If it is tight with 10 rounds, disassemble and carefully trim a hair (1/16" - usually no more than 1/8" (inch)) more off of the legs on the sub-plate ONLY. DO NOT cut anymore from the bottom of the follower or screw with the rail / track on the side of the follower.

 

 

Part four - final

For those who are curious, the spring in a factory 8-rounder is identical to a FBMG 20-rounder.

CIMG1229.jpg

Above - The top spring is from a FBMG 20-rounder, the bottom one is from a factory 8-rounder.

 

Also - The modified factory 8-round (now 10-round) follower works in my FBMG mags, making them 22-rounders.

 

Hope this helps

 

Macbeau sends...

Edited by macbeau
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thank you sir!...you just saved me a lot of time, i had be doing searches but had not found such comprehensive instructions anywhere.....you da man!

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I just finished muddling my way through this mod last night. I finally got it work reliably (not bind up after loading 6-8 rounds) by smoothing all the edges with a file as described by macbeau. I also had to remove 2 coils of spring to get enough extra 'space' in the mag so the bolt would cycle smoothly when the mag is full (10 rounds). Apparently the feeding lug on the bolt pushes the top round down about half the width of a round when it cycles to the rear. Until I removed the coils it didn't have that much travel left in the mag and the bolt would drag very heavily on the top round.

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I just finished muddling my way through this mod last night. I finally got it work reliably (not bind up after loading 6-8 rounds) by smoothing all the edges with a file as described by macbeau. I also had to remove 2 coils of spring to get enough extra 'space' in the mag so the bolt would cycle smoothly when the mag is full (10 rounds). Apparently the feeding lug on the bolt pushes the top round down about half the width of a round when it cycles to the rear. Until I removed the coils it didn't have that much travel left in the mag and the bolt would drag very heavily on the top round.

It sounds like either the bottom edge of the follower was probably contacting one of the lower coils on the spring, or you didn't trim the bottom "legs" on the sub-plate short enough. If you do the final step of compressing to follower all the way down with a seperate tool (like a Cresent wrench handle), it "arranges" the spring to guide around the inside of the follower. Again - you should only need to do this once after reassembling a mag.

If it held 8 before (without binding), it should take 10 easily without needing to cut the spring. The taper on the bottom of the follower helps a great deal too...

Just an observation - not a criticism.

 

Macbeau sends...

Edited by macbeau

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It sounds like either the bottom edge of the follower was probably contacting one of the lower coils on the spring or, or you didn't trim the bottom "legs" on the sub-plate short enough.

 

The bottom edge of the follower contacting the spring is a distinct possibility that I hadn't though of. :blush: Maybe it was turning the spring around - not removing the coils - that fixed the problem. I know the legs were short enough because they actually ended up about 1/8" shorter than the 'skirt' on the follower. When you put the two together (without the spring) the 'skirt' on the follower would sit on the sub-plate but the legs were still about 1/8" from touching the bottom side of the top of the follower - if you follow me ;)

 

I'll have to try it again later on another mag! :super:

 

BTW, thanks for making this post - I spent quite a bit of time searching through old posts to find all the info and pictures that you've consolidated here. Excellent!

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Is there any salvation for me ? I cut the mag follower off too short and eliminated the little guide .

Is your mag not working? If it's working, just count yourself lucky and enjoy it. If not, :cryss: ...

I haven't had a whole lot of luck in rebuilding on polymer that has been cut too short. JB Weld and similar products are usually way too brittle to give much long-term success, especially on such a small moving part .

I know Dinzag has "welded" mag bodies together, but I am not sure if he could build up something that small (.104" wide X .1" tall and about 1/2" long) and it have the strength you need. It might be worth asking him. Aside from that, you might need to find a new follower. :unsure: (I know - not what you wanted to hear...)

If you come up with a solution, please let everyone know about it.

 

Macbeau sends...

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For those who are curious, the spring in a factory 8-rounder is identical to a FBMG 20-rounder.

CIMG1229.jpg

 

That's pretty common with AK mags. For example, the hungarian 20(AMD-65) and even the 10(AMP-69) rounders have 30 round springs. - i found that out the hard way, ouch. I guess they see no reason to manufacture separate springs for all sizes, which sounds reasonable to me. Thank god, they couldn't force the 30 round spring in the 5 round AMP-69 mag, i have no idea how i'd have stuffed THAT back in there!

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Another solution to the need to modifiy the floor plate locking plate, the "sub-plate", is to just eliminate it...

 

And secure the floor plate from moving via a small wood/sheet metal screw near it's front.

 

This gains you a little extra space for good function of the 10th round (without quite as much needed removed from the follower bottom).

 

LG .

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thank you sir!...you just saved me a lot of time, i had be doing searches but had not found such comprehensive instructions anywhere.....you da man!

cool, thanks

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Great write up. Thanks!!!

I moded mine just about the same, except snipping off about 5 coils amounting to around 6" of spring. Bent and put back together, and it feeds great, feeds the first round great, and has just enough room for the bolt to come back and take in the first of 10 rounds reliably. I felt the tension on the spring and follower putting the spring in one joint at a time and decided it has way plenty of power to move bullets, and it ceratainly does.

 

Next project is to re-desing the Tapco T6 collapsable stock so that it has a stiff shock absorbing spring in there for shooting the .308. When fired, it should dampen the recoil of the .308 to some degree.

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I just finished muddling my way through this mod last night. I finally got it work reliably (not bind up after loading 6-8 rounds) by smoothing all the edges with a file as described by macbeau. I also had to remove 2 coils of spring to get enough extra 'space' in the mag so the bolt would cycle smoothly when the mag is full (10 rounds). Apparently the feeding lug on the bolt pushes the top round down about half the width of a round when it cycles to the rear. Until I removed the coils it didn't have that much travel left in the mag and the bolt would drag very heavily on the top round.

 

Just did the Mod. and had to cut off 2 coils to eliminate binding and everything rounds 10 feed great...thanks

 

Side Note: My Surefire 10 rounders did not fit Mag. well without filing off .040 at rear of mag contact area. Now they snap right in.

Edited by esource

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:cryss:

 

Waaaaaa!

 

I'd like to print these instructions with the pics.

 

How can we make the pics reappear?

 

 

This is why I hate photobucket and similar places...

 

Pics on forums stop showing up if the person doesn't keep their account active. I wish everyone would just attach their photos with their post, so if they disappear at least their post(s) are still up-to-date with current pics.

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Any chance the links to the photos can be restored on this DIY topic???

 

Yeah, the pics are a little critical to doing this mod. I was able to do two of them in 10 minutes using calipers, a grinding wheel and a knife to mark where to grind. I would be able to do it again using the modified ones as a reference but for somebody else it would be pretty hard using just the text.

 

If you guys really want I can take the pics of mine, makes some measurements and edit the pics to show the specs. I guess I will do this at work in a little while...

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Okay, so these are the dimensions from my magazine that I modified using the original directions. If you grind/file the follower and the bottom part to these dimensions you should be able to fit 10 rounds of .308 into the magazine.

 

One note, the following dimensions are in inches, I should have put that in the image but its too late now.

 

Don't count the lip on the top when measuring this, go from the flat part as shown in the picture:

post-19520-12670521921037_thumb.jpg

 

There is a little raised circle on the bottom of this, my measurement is including that.

post-19520-12670522007034_thumb.jpg

 

Anyways, work slow, and see if it will fit 10 rounds easily before getting down to my dimensions.

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My original pics should be back up and working again. If not, email or message me personnaly and I'll forward the tutorial with pics.

Macbeau sends...

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Kudos to you Mac, i was just wondering, if this can be done to an 8 for a 10, will it be possible for other mags? ie 10 to a 12, 25 to a 27 etc etc? Thanks again for educating us. :victory:

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Kudos to you Mac, i was just wondering, if this can be done to an 8 for a 10, will it be possible for other mags? ie 10 to a 12, 25 to a 27 etc etc? Thanks again for educating us. :victory:

 

It all depends on what the dimensions are of the follower, some are taller to make for improved reliability. I tried really hard to make my Saiga .410 factory magazine fit 5 rounds and ended up with a 4 round magazine that almost fit 5 rounds and feeds really unreliably. If you want to play around, take measurements first, of the ammo too. It'll be harder with double stack magazines but I'm sure you can come up with a formula of some sort, ie: see the height of 3 of the double stacked rounds in the magazine, divide by 3, and you will need that much more room. I could be totally wrong on how the math would work but that seems right. Do at your own risk, I'm half asleep and for some reason can't put the computer down. Gnite.

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Kudos to you Mac, i was just wondering, if this can be done to an 8 for a 10, will it be possible for other mags? ie 10 to a 12, 25 to a 27 etc etc? Thanks again for educating us. :victory:

I know you can make an FBMG 20-rounder into a 22-rounder, but they use Saiga factory followers. I did this to mine and they work just fine. I am not sure about SureFire, CSSPEC or Promags, but I am sure some improvement can be made.

 

Macbeau sends...

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ThirtyAught or macbeau.. Just ordered my 1st S308...

 

Can you measure the height for us with a ruler.. vs the caliper?? I don't own a caliper..

 

I see 1.088" for the follower (after mod) and .828" for the plate (after mod).

 

 

Albert

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OK so i've got a problem. I just bought a .308 and it came with 3 mags. I havnt used it yet i'm still waiting the 10 day "cool off" period required here in Cali. I took apart my three mags to do this alteration. One of the sub plates has the legs completely snapped off. The very bottom, where the spring clips to it is still there, but nothing more. Do you think that this mag will still work?

 

Chase

 

 

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