http://hometown.aol.com/spec4m/images/7-9d.jpg
Above with 20rd mag locked in a 30 rd and 2 20rds in front
This post is for those that want a cheap alternative instead of buying a 20rd mag from FBMG. The drawback is that because of the design of the saigas bolt, it needs to be able to push the rds down inside the mag as it goes rearward. An 8rd saiga mag is half the length of a m14 30rd. The first 3rds in the m14 mag are under so much pressure that the saigas bolt hangs up on the neck of the cartridge. As a result a 30rd mag is good for 27rd and a 20rd is good at 17. I have not done a 25rd mag but assume it should be good at 21rds. Personally, I don't like the 30rd. It's rather long and when fully loaded makes the rifle feel heavy and awkward. It was the same when I used it in my m1a and so it was chosen as my test mag, but it's great for photo shots.
Below with 30rd locked in.  
http://hometown.aol.com/spec4m/images/7-9a.jpg

Material needed: $15 M14 mil spec mag, present production seem to be as good as the old usgi, pre-ban after market suck. Must have a metal follower with feet, no flat plastic. Rolled steel bar, I had 3/8”x3/8”x36” from Lowe's, 1/4x3/8 would be easier. JB weld.

Tools: grinder, hacksaw, vise, file and dremel.

Take the mag apart. The ones I bought at a Salt Lake gun show had the springs put in up side down and the followers had a few burrs, most were on the left rear corner edge, file off. They are not as nice as the USGI, lacking the side dimples to hold the spring in place but still work. Nothing else is needed to be done to the follower.

First step is to measure in 1/4" at the rib (see pic) forward towards the front and 1/8" in around to front side. Remove this section.
http://hometown.aol.com/spec4m/images/86.jpg
http://hometown.aol.com/spec4m/images/83.jpg

You will also notice at the front corner, in the side pic of the newly painted mag, the paint has been rub off. This is a bind point when locking in the mag well and I have done 4 or 5 light  passes with the grinder on each side, but it still rubs a little.

Next remove the m14 mag catch (pic). I used the grinder to remove mine. That is all that needs to be done to the mag except to check the width and straightness of the mag lips. Spread is 7/16" from lip to lip. More or less will cause feed problems.

http://hometown.aol.com/spec4m/images/82.jpghttp://hometown.aol.com/spec4m/images/85b.jpg                      

Now to make the mag catches. These are longer than what some may think but the more metal to metal surface the stronger the jb weld will be. It's easier to make these on the bar of steel, then cut off. I hope the drawing is self explanatory.

http://hometown.aol.com/spec4m/images/scaninstr2.jpg

The front catch
I put a bevel at the front top because the original saiga has it. Also you must round the edges, you will notice the mag well slightly rounded. Make sure the finish on the front of the mag has been removed and scuff the bottom of the catch that has been made so that the jb will hold. Trust me the weld will fail if you don't have fresh metal surfaces. Position the top of the catch with what is left of the original height of the mag (not the round cut out) center in the middle of the mag, Jb weld. I also put Jb around the edge. Let it sit a day to dry.
After 24 hrs clean up any Jb weld that is on the inside of the mag, checked the fit by using the mags new front catch and rock the mag in. One wouldn't lock in and that told me I had not removed the 1/4" initially so out came the file, another had too much Jb weld on the front at the 1/4" indent front and I had to remove a little of that.  
http://hometown.aol.com/spec4m/images/85.jpg                      xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Back catch
Originally 7/8" but caused a problem. Cut to 3/4". When rocking into mag well also had to slightly ramp the front edge a little thinner. The catch Itself was left thick and a little long so that I could file to fit, and get the familiar click one hears when locking in a AK mag. To position put the mag together and load three or four rounds. Measure from the top of the round (left side round) 1 1/8" down to top of the mag catch (the side that is going to be  against the receiver). Sorry, ruler slipped in pic.

http://hometown.aol.com/spec4m/images/85a.jpg

This is it's Jb weld spot. Remember raw metal for Jb weld to hold. To finish the rear catch remove metal on the bottom not on the top, for this will put the mag higher into the mag well.

Problems
Front catch. This is not only the catch but the bullet guide/lift. If it's too high the rounds on the right side will not strip out of mag. Remove a little metal at a time. If the rounds impact on the lower part of the barrel mostly the left side rounds the mag catch is to low. I added some Jb weld to build up then filed a little at a time, problem solved.

Rear catch, if it is placed to low (mag higher in well) it cuts the number of rounds by one or two more. If the catch is placed high (mag is lower) the bolt will ride up on top as it try's to strip. To cure is to heat mag with torch pull off and re-weld into position.

I've locked my mags in and out of my rifle two to three dozen times each and the Jb weld has not failed. Also the first time that the 20rds were used I was not able to have the rifle function with more than 13 rds. As I loaded and unloaded the mags they have reached a point where they consistently feed the 17 rds without fail. Possibly the mag springs will break in and I might attain that 20rd mag with them.

I hope this helps any of those who wish to give it a try, and if it's informative enough feel free to stick it.  

This thing screams "POST ME"!!

Great info!  I should get my M14 mags tomorrow and will begin my attempt at modifying the mags.

Got to love JB Weld!

Got my mags, but I've going to be busy for a couple of weekends.  I'll post some pics when I get something complete.

By the way, I'm working on modifying a couple of G3 mags to work in the same way.  They look like they will work, although they will be tight!  The fronts would require the same sort of cutting.

I've seen G3 mags for as cheep as $3.70 each.  Although they are aluminum.

I dont reccomend modifying mags unless your a mechinest. M-14 mags are NOT made for a AK type rifle and even if you have success with one mag other (with differnt tolernce due to lot number and differnt makers) will not work. Just spnd extra money on relighable mags. Or better buy a M-1A or M-14 there a far better gun in the first place, they run from a Polytech M-14 at $500 to a Springfeild M-1A $1300.


Good Luck Anyway!!!!

Flashpoint1985

I dont reccomend modifying mags unless your a mechinest. M-14 mags are NOT made for a AK type rifle and even if you have success with one mag other (with differnt tolernce due to lot number and differnt makers) will not work. Just spnd extra money on relighable mags. Or better buy a M-1A or M-14 there a far better gun in the first place, they run from a Polytech M-14 at $500 to a Springfeild M-1A $1300. Good Luck Anyway!!!! Flashpoint1985

Well, what the hell fun would that be

Would this work with G3 mags?

I'm thinking of getting a Saiga and $2 mags sound too good to pass up.

I asked the samething, I don't see why it wouldn't work with the G-3 mag's in a vepr .308,but krebs custom said its a "no-go", that it would take to much work with the reciver. If you do try it please let us know how it go's.

Wow nice guide, I might pickup a couple of mags and do this.

I'm having good luck with M14 mags, but I use the original rear tab, with a little grinding, and a piece of 1/4" Lexan for the front catch.  Fits good with solid lockup.  

I went through several G3 mags and a couple FAL mags trying to get them to go, but they just have too many problems to overcome.  

For a straightforward conversion, use the M14 mag.

Will silver solder work on these mags??

I just bought a M14 mag and was going to attempt this (and then repeat many times if it works) but then I noticed the taper on the front of the Siaga mags, as viewed from above.  The M14 mag does not have this taper and the mag well is tapered to match the factory mags.  The front of the M14 mag just doesn't fit.  I will have to dremel the front edges of the mag well, and I didn't see anything about having to do this in the post above.  Didn't anyone else doing this mod have this problem, and if you did widen the mag well in front is the lockup on the factory mags now sloppy?

Thanks!

#1, silver solder works. I put thr front of the mag in my vise, you can pinch it down a little and there is still room for the follower. I recommend that you DO NOT modify your rifle, only the mags.