Sunday, 11 October 2015

Oppan Pistol Style!

The AK platform is an iconic one, and one that I personally like a lot. Over the summer I bought the TM AK-47, and ever since I've been looking for a metal body for it. I don't really enjoy the plastic one that much, and it's starting to crack anyway. For this purpose, I bought an old, non-functioning second hand AK that had a Guarder body on it. My plan was to strip the internals for parts and use the body for the 47.

The previous owner had, however, installed an AR stock on it using some creative brute force, and had cut down the barrel all the way up to the gas tube. The gun had also been painted black all over and later at some point had also had some dark grey splashed on it from another paint job.

The AK stock attachment point had been cut down and the AR stock tube was attached via some large pop rivets. The sling mount had also been taken off, leaving a simple hole on the side.

I didn't exactly fancy the attachement, and since the stock attachment had been ruined, putting on a full AK stock was not really an option.

This project took its first steps when, about a month ago, me and my SO went to a local convention dressed in some Mad Max inspired wastelander gear, and the AKs were an obvious choice for the costumes. I gave her the TM and took the new shorty for myself. To make it even more interesting, I cut down the rest of the stock attachment and added a simple sling mount by bending a nail to fit the slot.

After this, the gun was left alone, until now. Since I could not use the body for the TM, I decided to go another way. I'd stumbled on the Draco carbine on the Internet, and decided this beaten up veteran would be the perfect material for such a build. My plan was thus to build a very short, stockless AK to use as a CQB gun.

Internals check and update

I stared off by cracking open the gearbox so I could see what I had bought. Inside were steel gears, a swiss cheesed piston, a motor that didn't turn and pretty much no lube of any kind.

The motor didn't react at all even with power clearly running to it, so I declared it dead. I found it easier to swap it for a stock JG motor that I had lying around from the AUG DMR build than to try to figure out what was wrong.

With the new motor I got the gearbox to turn very nicely on a 7,4V LiPo, but once I chronoed the gun, it was shooting way too hot for CQB.

I found out I could use almost all of the parts on this build that I had left over from the AUG, since the piston, spring and cylinder from that were also very useful here. The cylinder that was very wrongly ported for the AUG was a great fit for the to-be short barrel of this build. The spring was between an M90 and M100. I did a simple AOE correction with a nylon washer and achieved a very nice result by just using the one.

Since I was building a CQB weapon, I though a bit higher ROF would be in order, so I put in 13:1 gears and a sector clip from CORE.

The gun also came with a self made mosfet but no fuse, so this was the perfect chance to try out the new flat fuse holders and 30A fuses that I had ordered earlier.

External work

As I was planning to build the shortest AK I could, I had ordered a new AKS-74U style front sight and gas block some time ago.

Also on the list of things to definitely take care of was the rear of the body, which at current had a gaping hole on the end, as well as the hole for the sling mount on the side. I had decided to close up the hole on the side and fit an end plate with a new sling mount. I stared off by filing down the nubs of the stock attachment point.

Lots and lots of filing later I took a metal plate from a pile that I had collected somewhere years ago. If I remember correctly, these were back plates for hooks that held cat food samples on a stand somewhere, and I'd held onto these for years. Not in vain, though! The plates had a nice hole right in the middle, which was perfect. 

The plates were also soft enough to cut through with tin snips, which made my work easier. After cutting the plate to size I attached it with chemical metal, and used the leftovers to fill in the original sling mount hole.

Once the metal had dried, I went back to filing and then sanded everything down with wet sandpaper to achieve a smooth surface.

Any gaps that were still left over at this point I filled with filler putty and re-sanded. My hope was that once painted, my additions would be invisible. The sling plate I had in mind was one that was originally intended for an P90 or MP7 that I had bough together with the front sight. It seemed perfect for the job, since it came with an attachment bolt and I had a fitting nut for it. The hole on the back plate had to be enlarged with a round file a bit for a perfect fit, though.

As the rear was now well in hand, I moved onto the front end. I had to shorten both the outer and the inner barrels as well as fit the new sight and gas block, as well as re-finish the hand guard and pistol grip. To start, I noticed the front sight would not fit on the end of the gun's gas tube, so I had to file down the hexagonal attachment point quite a bit.

In fact, I had to file it down so much that in the end I gripped the gas tube (which in reality was an upside down half pipe) so hard that it simply gave in. To be honest, at this turn I did sort of feel that everything had been going suspiciously smoothly up until this point.

Luckily, again, I had stockpiled stuff from before, so I had on hand a short metal pipe that fit the inside of the fake gas tube perfectly. After applying some more chemical metal, I was back in business. The pipe fit inside the receiver and was held in place by the chemical metal, while the pieces of the half pipe and the end cap were glued onto the pipe using the same material.

Now that the gas tube was in once piece and the front sight fit onto it, it was time to check the length of the barrel by using the barrel mounting bracket which would also hold in place the lower hand guard piece. Naturally, the front sight and the bracket were completely mismatched. The front sight had a piece that would not fit in the notch on the bracket, as well as a short fake tube which the bracket simply had no place for. 

You may have guessed it, but I went to the saw, the file and the chemical metal once again. I first did a rough cut so I could actually fit the two pieces together.

And then used the chemical metal to form an easily malleable surface that I could grind into shape.

The end result was a more than pleasing fit, so I could finally move onto the barrel. The cut done by the previous owner was not a very pretty one, so I decided I would do so much better by using a proper pipe cutter.

Had I been smarter, I would have cut the barrel from the other end, but because this is not the Let's Do Everything Right On The First Go blog I cut down the barrel from the front end, thus getting rid of the narrow front section which, you guessed it, is the one that fits inside the sight base. My only choice was, again, the file and coupled with a lot of patience. I have never before, up until now, wanted to own a lathe so bad, or at all, in my life.

Later on I also noticed I had cut the barrel a couple of millimetres too short, and had to file a bit more off in order to drill a hole for the screw that would actually attach the front sight onto the barrel. Once that was done and I had drilled the hole with possibly the dullest drill bit in the world, I went to happily tap it with a steel screw (because the barrel was aluminium, I was certain I could tap it just by turning a screw into the hole). That went nicely until the screw head broke off, leaving the screw in the hole. For a few moments, after a session of middle to severe level swearing, I tried to drill through the screw. No luck, so I drilled another hole. Which was not in the right spot. Third time's the charm, damnit.

Now that the front section finally fit together somehow, I could cut down the inner barrel, put the whole thing together and test fire it for the first time. The funny thing about pipe cutters, however, is the fact that they tend to, by their very nature, squeeze the material, which I did not entirely take to heart until the chrono failed to show any results.

I had a phillips screwdriver which had the perfect size to act as an ad hoc reamer, and soon the BBs would actually fit through the barrel. The technical side of things was now done and I could finally move onto the finishing stages.

Finishing up

I started off by setting up a paint shop in my bathroom, and spray painted all the external parts with three coats on all sides.

Instead of the original black, I wanted the hand guards and the pistol grip in the original colour so, off I went, sanding away until all the paint was gone.

The end result was, unsurprisingly, rather dull in its appearance. I decided to lacquer the surface for a proper finish.

As a final touch, while waiting for the paint and lacquer to dry, I decided to polish the bolt carrier. It was more work than I though, but it adds a nice little extra effect on the gun.

I was first planning on using the regular AK-47 muzzle device on the gun, but it did not look right, somehow, so I opted for an extended bird cage style. The colour is not the same as the rest of the gun, but I actually like it better this way.

The rear sling mount works very nicely for a gun this size and can easily take either a modern hook system or a more classical AK style sling.

Since the gun now shoots about 20 rps, it's good that I have some spare magazines.

I have to say, I'm damn happy with the results I got from this. Altogether I think this project took up around 15 hours to finish over the course of four days.

I'd love to hear your thoughts and opinions on this project as well as read about your own custom builds! Until next time, folks!

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