AK magazine fitting issues and Magazine catch issues

[fredieusa]

I was talking about it to yet another friend and thought it is about time started a thread with pics and all, as it is only a matter of time someone will bring this up. Below is how I (used to) do it, please share your methods and suggestions.

For folks that may be new to this, please do not use live rounds. Also the general disclaimer applies. So be aware that messing with guns can cause you serious injury, up-to and including death!

Ideally all magazines should work, but there are variances that exist. Some issues that arise are fitting, seating and locking in the mag-catch and positive reliable feeding.

For this entire exercise, I use at-least four different makes/models of mags – Chinese, European, Plastic/composite, US domestic made etc as you want to cover a wide range as you do want them all to work.

Fitting the magazine well. If any of the magazines listed above encounters resistance or is not able to be inserted, file the edges on either side evenly. The magazine stabilizing tab may also need to be filed down. The goal is to get the fattest one in there, but do not over file as that will lead to excessive wobble in others. Also make sure you are not working on a 5.45 receiver and trying to fit a 7.62 mag in it, unless that is your goal.

Edited to add: Use some sand paper on the sharp edges after filing, this will prevent magazine damage, scratches etc..





Mag-well height (front to back). On occasion a magazine will not want to go in and offer resistance at the rear end. This requires filing at the rear edge of the mag well. Ideally this is done when the mag catch/Trigger guard is already in place. This means the selector stop plate also gets filed/recessed as the edge recedes.



Filing down the trunion lower ledge to make the mag fit is not advisable as that changes the relationship between the rounds in the mag and the distance they travel to the chamber when stripped by the bolt, more on this in a bit. This is why it is important that the trunion is aligned straight with the front vertical edge of the receiver.

[fredieusa]

Depth (or height) of mag inside the receiver. This is determined by the selector stop/ receiver area where the magazine knob rests on. This is indicated by the arrow below.





There is a lot to discuss when it comes to the correct depth of the magazine inside the receiver. Our main concern now is how well the magazine seats and secures, but more importantly how the correct depth facilitates proper cartridge stripping from the magazine by the bolt lug.

Before starting it is best to note how the mags adjust as is. Engage the mag and it should latch securely on the mag release lever. If the magazine is not able to secure properly and seat area flush, we have a few decisions to make. Either the top of the magazine release lever needs to be filed down, OR the selector stop/receiver area (as shown in the pics ABOVE) where the magazine lug rests needs to be milled out.

DO NOT FILE THE MAG RELEASE JUST YET - WITHOUT DETERMINNG THE CORRECT REMEDY, as this will lead to a sloppy loose mag fit if it is later determined that the selector stop/receiver area where the magazine lug rests needs to be milled out to raise the height of the magazine inside receiver.
So first rest insert the mag and have the mag ledge rest on the selector plate/receiver (maybe at this point the mag release in not properly/fully engaged – this is fine at this point)

In the pic below you can see how a mag is fully seated on the selector stop/receiver area but the mag catch lever is not fully engaged as there is not enough space between the selector stop plate and the lever at its resting position. Do not file down the magazine lug to make it fit, that defeats our whole exercise and purpose.

Pic ZZZZZZ

[fredieusa]

Note the relationship between the bolt head and the rounds in the magazine (do not use live rounds, use dummy or even empty casings which are properly seated)

The cartridges on both sides (whether feeding from the left or right) should have a positive contact with the bolt lug to facilitate a reliable stripping from the magazine and chambering.









If the bolt lug is not making sufficient contact with the cartridges, the mag azine needs to be raised just a bit. This means we need to mill out the selector stop/receiver area where the magazine lug rests. These areas are milled/recessed by using an endmill. The cut should be wide enough to accommodate the magazine locking lug comfortably.

[fredieusa]

By now the pressure on the magazine release should have eased if it was not catching securely.

If the magazine catch still does not engage completely you can start to file the top of the mag catch lever using a file or a dremel wheel that will fit in there.

If the material removed is in excess, it will cause the magazine to be floppy and cause it to drop down in the mag-well leading to issues pertaining to feeding. In this case you will just have to get a new mag catch lever.

Pic ZZZZ

[fredieusa]

Some other points to ponder over..

In stamped receivers, the center support will be very close or even touching the mag, this is fine. As long as it does not interfere to the point where the level starts to change, you are fine. On some makes, due to variances in trunion, magazine and receiver, the center support sleeve has a flat side. This is common on Yugos.

PIC ZZZZZZ

At normal position, when the magazine is properly seated and latched, and the cartridges are properly seated/loaded in the magazine, they appear to be slightly pointing upwards. This is normal and important as it facilitates reliable chambering of the cartridges as the angle at which the cartridges travel from the magazine to the chamber is unique and all surfaces in contact during this process matter.

Understanding the purpose and relationship between parts will solve most issues. It is important to know what else gets effected if any particular thing is changed. These principals apply universally through-out all weapon platforms, not just AK.

[nicoroshi]

Nice write up Fredie.
Sticky????

[Gowking]

Another good tutorial!

-MRA

[big103]

Nice work up. Sticky

[atsaubrey]

Great write up! I think this should be stickied as well. I will mention, I have never had to file the actual mag well in any of my builds.....always a first though, I aint done building.

[tujungatoes]

good write up fredieusa.

The idea of an AK sub-forum has been discussed before. I think the final determination was that the gunsmithing section pretty much is the AK sub-forum already. We hang out in here, and the tacticool AR guys pretty much own centerfire rifles. If they started dividing it up there would just be be 30 different sections. Most of which would never move.

If only I knew a moderator *cough* 69mach1 *cough* that could maybe clean up and collect the AK refrence threads into ONE sticky.

[atsaubrey]

good write up fredieusa.

The idea of an AK sub-forum has been discussed before. I think the final determination was that the gunsmithing section pretty much is the AK sub-forum already. We hang out in here, and the tacticool AR guys pretty much own centerfire rifles. If they started dividing it up there would just be be 30 different sections. Most of which would never move.

If only I knew a moderator *cough* 69mach1 *cough* that could maybe clean up and collect the AK refrence threads into ONE sticky.

ok ok two toes


lol

[tujungatoes]

two toes? Hey there buddy, I still got all 11 of 'em.

[nicoroshi]

thanks guys.. so ???? whats your tricks on tweeking stuff.. please do share..

A good eye, a black marker, and a good set of needle files.
Most only require minor tweaking to get running flawlessly.
If they pass head space check, tilt test, and 10 round cycle test in the shop then 99% of the time they're GTG.
I do tune my FCGs (85% of hammer width is the distance between trigger, and disconnector hooks), sharpen my front sight post to a point, and cut a bolt hold open in my safeties for all my builds.

[4thSBCT]

fredie needs his own section called Fredies corner.

[fpasuncion]

fredie...this is exactly what I was asking about in my PM. I haven't been on Calguns in awhile and didn't know you had this write up. So...back to the drawing board. Pop out some rivets and add the selector stop PLATE!...lol