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Factory 8 rounder to 10 rounds.

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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?



That is a DEFINITE....probably!

My guess is it'll work just fine as those lower legs just keep the spring from twisting (torquing) under compression.

Macbeau sends...

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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).



First - magazine disassembly.

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


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.



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.)


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.



Part two

Here is the factory follower.



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


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.



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.


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).





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.


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.


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.


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.


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...

Thanks a bunch! It did indeed help. Went out and tried out the new gun and newly modded mag...both worked great. Put 60 rounds through both and not any glitches at all.

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One small additional tidbit that might help those experiencing issues. When cutting the two "Legs" you are creating a flat surface for each that the coils might be hanging up/binding on under compression. This would occur early on as your inserting rounds and would prevent that last 1 or 2 from going in. The simple solution to this is to bevel the top edges of the legs with a file or similar. I used coarse sandpaper to bevel the three side of each leg slightly.

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IF you manage to cut those guide tabs off, you may be able to recover. Go to a hobby shop like hobbytown USA, they have shaped styrene plastic pieces.


Find some the right size and use 2-part epoxy to attach them. Or, go to litkoaero.com and order the Craftix #33 glue. That stuff will bond just about any 2 plastics together. Be extremely careful, however. If any of that glue gets between the follower and the mag body, you're doomed.

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Thanks a lot for the great thread! I went down to Harbor Freight and bought some $9.99 digital calipers and s new circular saw set for my Dremel Tool I also got there and used your great step by step method. I had 5 mags to convert and after I made the alterations to the first one and made sure it worked, I used it as a templete and I had them all done in no time! Thanks again!

Edited by Berzerker2
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Just did all 3 of my 8rnd mags lastnite finishing off my Great Lakes X-Mas Ale(expires tommorrow...). Super easy and only takes literally 10 minutes for each. Glad I found this write up! Simply awesome!

Edited by J308
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I just wanted to say thanks for the detailed post that made this very easy to accomplish. I had a CALIPER so with your step by step instruction it was very easy and fun to do. I actually stumbled on this post a few months before I even joined here. then I was here for a while and rediscovered the post so that is the reason for the late thank you, better late than not at all..

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For the rest of us, no change, at this time...!


Macbeau sends...

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