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Krytac PDW M MKII - Custom Stock & Drop Stock - Mod


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I thought I would make a post about modifying the stock on a Krytac PDW-M MKII as I couldn't find any information about it online when I was researching and preparing for this mod.


So if you are interested in modifying the stock of the PDW-M (Custom M4 Stock or Drop Stock) and are looking for a quick tutorial you have come to the right place.


Let's start with just a standard M4 custom stock and move on to the drop stock after.


The first thing to say is this mod was overall 100% worth the time, money and effort.







Why modify the stock?


Let's face it PDW stocks have a reputation for being not so great! I mean sure they work… but they are not ideal. 


After using the Krytac PDW-M for a while I had a few issues with the stock. Firstly even when it was fully extended it was still a little short. This made for a firing potion that felt very unnatural. Like holding my body in a stress position. The but of the Stock also does not sit well in my shoulder. 


Being able to fit a standard M4 Stock in place of the PDW Stock helped solve these problems.



How to modify the stock


This mod is really easy to do. 


If you Google the Part Diagrams for the Krytac PDW and the Krytac CRB you will see that the Receivers are identical. This means that the standard Krytac Trident M4 Buffer Tube from the CRB will fit on the PDW with no modifications. Just don’t forget to also grab the Sling Plate that goes between the Buffer Tube and Receiver.


As far as I can tell the official Krytac Buffer Tube is a standard M4 Buffer Tube. So you might be able to save some money by getting a cheaper aftermarket M4 Buffer Tube. I would recommend you double check the dimensions before buying any aftermarket parts. I had a little extra money and just went for official Krytac parts for continuity's sake.


Removing the PDW stock is easy. There is just one cross head screw inside that battery compartment.


Installing the Trident M4 Buffer Tube is a little tricky and it takes a little dexterity to get the wire and washer lined up with the Buffer Tube. Again it's basically just one cross head screw and a washer. You will need a long screwdriver to fit down the Buffer Tube. I just grabbed one on Amazon for about £8.


Congratulations… You now have a standard M4 Buffer Tube on your PDW and any aftermarket M4 Stock will now fit the rifle.


Again for the Stock I grabbed an official Krytac Trident Stock but I’m planning to try some aftermarket ones later on.


Let's move onto the drop stock…


What is a Drop Stock Adapter?


In short a Drop Stock Adapter lowers the Stock of the rifle about an inch allowing you to get any optic/sights up at eye level without using annoyingly big risers.




I also really love the look of a drop stock and it does look awesome on the PDW IMO!


My favourite Red Dot doesn't really have any legs and sits really low down. This in combination with my Dye Mask makes it impossible for me to get my eye behind the Red Dot without the use of a stupidly massive riser. It completely ruined the look of the rifle and was not very practical.


Lowering the Stock eliminated this problem.



How to Drop Stock a Krytac PDW?


Again this mod was really easy to do.


First you need a Drop Stock Adapter. I grabbed mine from the link below.




There are a handful of people selling these online so have a look around.


The adapter just fits between the Sling Plate and Buffer Tube.


As with most custom 3D Printed parts it will need sanding down before you try to fit it. Even with a hammer it would not fit the rifle without sanding (I do not recommend you try and hammer it on! You will break the adapter!). I found some coarse sandpaper and little model files worked best for this. You can grab a set really cheap on Amazon. I spent about 30 minutes sanding it while watching a movie and then it fit just fine.


With some Rifles the round part of the Receiver the adapter fits onto (The Buffer Tube Mounting Point) will be slightly too long for the adapter. I had this problem with the Krytac PDW and my choice of Adapter. 


This creates a small gap between the adapter and the Receiver that the Sling Plate can rattle around in (Annoying!!!). It was only about 1-2mm wide but it was annoying me that it did not sit flush with the Receiver and Sling Plate.


Drop Stock Tutorials online recommend cutting off a small amount of the Buffer Tube Mounting Point on the Receiver with a Hacksaw to fix this problem. I really did not like the idea of that! I got around this though by doubling up on identical Sling plates to fill the small gap and it seemed to work just fine. As you can see in the above image I have two identical Sling Plates together. 


The only other thing you will have to do is modify the Sling Plates. Normally the wire will go directly out of the Sling Plate hole into the Buffer Tube. Now with the Drop Stock Adapter the wire has to bend down 90 degrees under the Adapter. I was unable to find a Sling Plate (in stock) online with a hole big enough for this.


This was an easy fix though. I just used a cheap Hacksaw to cut the bottom of the Sling Plates out. Shown by the red Box in the bellow image. No need to even do a good job (unless you want to :p) as none of it can be seen once the rifle is assembled. You will need to file down the sling plates after cutting. Mine were unexpectedly sharp and I now have a really bad cut on hand. They were so sharp I didn’t even know I had cut my hand until there was red all over the floor. So be careful.





The end results.


I am really happy with this mod. Having a real adjustable stock makes for a much more comfortable firing position. The shape of the new Stock also sits better in my shoulder compared with the PDW Stock. The rifle also feels way better balanced. The new Stock seems to distribute the weight of the rifle better. 


Overall it’s a very noticeable difference. The second from longest Stock position seems to work best for me with my choice of Stock.


The Drop Stock has done its job and I now have my Red Dot on the rifle at eye level with no stupid risers. I thought it might make the rifle feel a bit off, balance wise. You really don’t even notice it at all holding the rifle. Everything seems to be on nice and tight and I don’t think it would break.


Looks wise I’m also very happy. IMO the rifle looks way better with a standard M4 Stock and I love the look of the Drop Stock.


So I would 100% recommend this mod to anyone who has this rifle.

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I guess an added bonus is the iddy bitty batterys are no longer needed too 😎

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2 hours ago, Barny said:

I guess an added bonus is the iddy bitty batterys are no longer needed too 😎


Yep. Way more choice for battery. Basically any kind will fit in the Krytac M4 Stock.

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