How to Void your TAPCO Intrafuse Mag Warranty
This tutorial describes how we reworked a perfectly fine TAPCO Intrafuse ten round AK-47 magazine into a five rounder. Yes, a five rounder...
Why? Why?! WHY?!
While we would like to chalk this one up to some sort of Freudian compensation behavior, the truth is that we needed a subcompact mag for our upcoming "Big WASR-10 Ammo Accuracy test". The ammo test will require the project WASR to be strapped down in a Hyskore Dangerous Game Machine Rest. This is a high end rest, but since it was designed for hunting rifles and it does not leave a lot of vertical clearing below the gun. The TAPCO Intrafuse 10 round AK-47 magazines that we wanted to use for this test were great but turned out to be too long to be changed out while the gun was strapped down.
Figure 1: With the WASR strapped down the 10 round mag can not be removed.
TAPCO sells a 5 round version of the Intrafuse AK-47 magazine, but after checking with the friendly folks @TAPCO client relations, we found that the five round magazine uses the exact same body as the 10 round magazine (with a different follower to lower capacity).
Not wanting to shop around for other 5 round mags that might be too large for our purposes, we decided to take matters into out own hands. Oh yeah; while reading this tutorial please realize that we are not gunsmiths nor lawyers. You and you alone are responsible for your own actions. 'Nuff said!
Lets Go Void That TAPCO Lifetime Warranty!
First order of business is to disassemble the mag. If you have another identical mag, take it apart too so you have one to compare against while you work.
Size up your Opponent
Take a moment to study the individual parts and see how they work. Notice the thickness of the "rail" on which the base plate moves check out the lack of rail on the slender part of the mag. Look at the base plate to see that the indent which goes on the rail is only on the straight part.
Now pay attention to the sharp bottom edge of the follower which prevents the spring from getting stuck. Also note that the cut on the bottom of the follower is slightly angled to follow the curved design of the AK mag.
Figure 2: This is what you are up against...
This mag is made of a very strong composite material, but it's easy to file, chisel, cut and saw. If you are unsure about how much material to remove, play it safe - cut, try for size, then cut some more. Baby steps. Still feeling up to this?
First Cut is the Deepest
Okay, school is out. Let's break out a hacksaw (with a blade designed to cut metal) and go to work! Start by making a straight incision along the underside of the center rib. As this rib will become the rail for your base plate you do NOT want to cut off too much. Once you are done you'll want your new rail to be slightly thicker than the original. If you cut on the outer edge of the rib you should be good. To ensure a straight cut we strongly recommend using some sort of miter box. Feel how smooth the saw goes through. Nice!:-). Resist the urge to grind the rib down further until you are done with the next step!. Resist the urge to toss the original bottom part. You'll need it to compare against later.
Figure 3: Make a straight cut along the bottom of the center rib.
If you look at the original rail on the part you just cut off, you'll notice that the vertical reinforcement strip of the mag does not run all the way down to the rail. It stops just short of the rail to create an indent that allows the floor plate to slide past. In our enthusiasm we started out using a shape edged metal file, which worked, but we found that a really sharp straight edged wood chisel gets a much straighter cut. Use the chisel to slowly trench down until you have an indent of the same width as the original. Finish it off by running a folded piece of fine sandpaper through to get rid of any burrs.
Now you can work on the fit of the base plate. It should go on with some encouragement, but not too smooth. If it's too big you'll need to sand down the bottom of your mag. Do this by moving the mag in a circular motion around on a piece of fine sanding paper. Make sure to hold the mag straight down. When you are done with this step the base plate should slide on most of the way until it hits the front of the rib that sticks out.
Figure 4: Use a sharp chisel and possibly a small file to cut an indent to allow the base plate to pass the vertical reinforcement strip
Take a look at the original bottom of your mag and compare it with your new "bottom". You'll notice that the original does not have a "rail" on the slender front portion of the mag. Also note that the original bottom is slightly slimmer and shorter than the new "bottom" of your mag. This difference will prevent your base plate from sliding on all the way. Lets fix that. Start getting rid on the remainder of the horizontal rib along all of the slim portion of the mag. We used a file and a chisel. A round edged file is handy for that pesky part where the mag widens.
Figure 5: First get rid of the rib along the narrow part of the mag.
The last part of this step involves creating a ledge for the slender part of the base plate to rest in. This is necessary because the mag is a bit wider where you cut. If you'd paid attention in Geometry you would have understood this...:-)
Figure 6: Now cut out a ledge along the narrow part of the mag for the base plate lip to rest.
The ledge needs to be cut along the front and sides of the narrow part of the mag. It needs to be just wide enough for the lip of the base plate to fall into. It does not need to be deep - about 1/32 will do. While you are cutting the ledge, keep trying the base plate on, so you'll know when enough is enough.
Figure 7: Are we there yet? Keep trying to prevent cutting out too much material.
When you are done with this step you should be able to reassemble the magazine and have the floor plate square peg snap into the base plate square hole with ease. Congratulations; you now have a beautiful three round magazine...
Time to adjust the follower to increase the magazine capacity by two rounds. To do so we need to cut off just shy of 1/2". This will give us room for five rounds plus a little wiggle room for easy loading and smooth cambering of round #1. Due to the flexible material used for the follower and the angle of the cut, this could be the hardest part of this mag conversion.
This is how to make it easier: Find a piece of wood that fits snug into the follower without stretching it. Then scratch or draw a line parallel to the current bottom of the plate. You'll want to remove just a little less than 1/2". Now use the miter box to cut thought the follower with the piece of wood inside.
Figure 8: Don't try to do it this way. Put a piece of wood in right away and make a STRAIGHT cut, parallel to the current bottom of the follower
Finish the cut with some light sanding. Then use a chisel or even better a Stanley knife to recreate the sharp edges that the original follower bottom had. These are needed to guide the spring and prevent it from catching on the bottom of the follower. Don't cut it down too much as this will weaken it. Use the original bottom as your example.
Figure 9: Look at the original follower bottom to determine how sharp to cut the edge
We used snap caps to test if the bolt strips the rounds off easily, which it does. We considered shortening the spring to prevent metal fatigue caused by overstretching due to the shortened follower, but then we decided that we'd rather get a beer. When the Zombies attack these mags are going to stay in the safe anyway. We tested the mini mag at the range and so far it works without fail.
We considered mimicking the cut out in the back side of the original follower has but we could not figure out what the intention of the cut out was. Maybe we should have paid more attention in school as well.
Because "looks" matter, we used some car polish to smooth things out and some "Back to Black" bumper shine to spiff things up. After that we wiped everything totally dry and reassembled.
If everything worked out you'll now have a "Custom Subcompact Tactical Five Round Ammo Delivery System":-). If things did not work so well, we suggest you reevaluate your practical skills, have Cup-of-Noodles for dinner and get over it.
Figure 10: "Custom Subcompact Tactical Five Round Ammo Delivery System" reporting for duty! Sir!
Figure 11: And this is what we were after. Less mag sticking out of the gun!