Arthur’s TW5SD6 Conversion

There seems to be renewed interest in Systema’s TW5 platform. Once written off as unrealistically heavy and lacking in mag capacity, PTW owners have been looking around for an alternative to the M4 and finding other platforms rather lacking in finesse and quality.

Here, Arthur takes us through the steps he took to convert his TW5 into and SD6 variant.

“Due to the lack of Systema parts for the Systema TW5, it is often necessary to customise RS or Airsoft parts for this system.

In the following text, I’ll explain what’s required to convert a
Systema TW5 into a custom TW5SD6.

First part is the retractable Stock.

In my case I was lucky to get a new RS one (not from H&K itself, but from a
licensed production).

First step was to remove the rubber buffer – the item is not needed in our case.

Rubber is gone. The two nuts are removed too, to further disassemble the stock. Keep both of the nuts for reassembly later.

Now the stock can be disassembled. You’ll end up with these parts:

The next step is to fit the stockholder on the TW5 receiver. Without other modifications, the holder could only be fitted like this:

The problem is, the red area prevents the holder sliding fully onto the receiver.

So, a modification has to be made to the receiver.

I was unlucky and had to file the area down by hand, because my lathe refused to work.

After filing the receiver, I had to hollow the holder a bit.

The next step is to file down both sides of the retractable stock by ~2mm to fit the
guides in the receiver.

Now the whole thing has to be reassembled again…

In my case i was happy to get my hands on a ICS SD6 frontset. First step was to fit the plastic frame to the TW5 body.

I used two of the orginal ICS scews in the top section and two new ones in the lower section.

The plastic frame had to be dremeled where it sits on the receiver.

The ICS front sight section had to be filed out a bit to accept the Systema cocking lever part.

The area where the outer barrel sections come through had to be widened too.

The ICS supressor attachment part had to be modded like this, to let the Systema flash hider pass through:

Now the front section can be assembled. The Systema flash hider is screwed through the ICS suppressor attachment, into the Systema outer barrel.

Some small plastic parts to prevent the plastic frame sliding back.

The suppressor and the handguard are attached.

Job done: a new born Systema TW5SD6.”