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turok_t · November 18th, 2014, 23:45

..:::TUROK'S MP5K STOCK ADAPTOR MODIFICATION GUIDE:::.

Here is a summary of the modifications in adapting the rear stock adaptor to accommodate a 416C retractable stock for the VFC MP5K. At first, the task was daunting given the number/level of difficulties and contingencies involved, but when there is a will, there is a always a way. My planning and execution had to be impeccable, not some half-assed croaked DIY that is held on by glue that ends up like a croaked broom stick. After a lot of planning here are the major steps I took. Here are the 2 items I used:

Action MP5K Stock Adaptor for Marui AEG

AABB HK416C style stock

Note: TSC has also released Type A and Type B VFC/WE MP5K stock adaptor; however, it doesn't allow the 416C endplate sling loop to be attached. Also, these were not considered as it made the stock adaptor stick out more from the MP5K rear.

Using the Action MP5K stock adaptor as the base for my rear stock adaptor, it had to be heavily modded. Given that the middle section of the rear surface is raised (look above), the 416C sling loop endplate will have a gap when placed over the stock adaptor. As such, the entire raised platform was required to be removed. I pretty much milled out this section by hand.

The surface was more refined to a smooth finish, and cracks/crevices were filled with JB weld for a more even surface. You can image the degree of difficulty in removing material from around the tabs that secure the buffer tube in place, and yet it had to be completely flat for the endplate sling loop to sit flat.

On the other side of the Action stock adaptor, the pin holes are housed within the raised posts as shown below. However, given the narrow size of these posts and diameter of the pin holes, there is some movement when the rear VFC pins are placed through.

These were subsequently removed and grinded down. I wasn't too concerned with the overall final finishing as it would be covered up anyways.

The surface was further refined and leveled to ensure that the endplate sling loop would sit completely flat against the adaptor with no gap.

Next, the entire plastic VFC buffer block was removed from the PDW stock. The goal was to use this buffer block to adapt it to the stock adaptor. In order for it to fit, the entire back portion of the buffer block had to be removed. But this wasn't simple, because the entire surface needs to be completely flat and modified to just the right height. Failure to do so can cause the buffer block to sit croaked/angled against the stock adaptor, which in turn will render the 416C stock croaked as well against the main body of the gun. On the other hand, if the depth of the buffer block was too low/high, the pin holes will not align, or there will be a gap between the body of the gun and the stock adaptor.

Here is a picture of the buffer block (secured by both rear pins) being test fitted for depth within the MP5K. Notice how the surface is completely flat.

Now that the hard part is done, the next step was to mill a crater in the stock adaptor to accommodate the flat screw post that secures the yellow buffer in place.

Here it is, the screw post sits perfectly within the crater, and lies perfectly flushed against the surface of the stock adaptor.

To secure the buffer block onto the stock adaptor, I retained the original two hex screws from the buffer block, drilled two holes onto the stock adaptor and tapped threads into these holes.

The two holes that were drilled above need to align perfectly with the holes on the buffer block. If I messed this up, the buffer block would not sit aligned on the stock adaptor, and hence, would mess up the alignment of the stock with the body. I had one shot to do it correctly or else everything I've done thus far goes down the drain. Here is the result.

Once that was completed, the entire stock adaptor was further refined with 220, 400, 800, 1000 and 1500 grit sandpaper in preparation for airbrushing.

Here is the stock adaptor after one coat of Duracoat HK black paint. Again, wasn't too concerned with the finish as it would be concealed at the end, but nonetheless, not bad.

After the painting, the two screws that secured the buffer block on the stock adaptor were shortened so they were flushed against the stock adaptor. Again, if the two screws were protruding, it would block the sling loop endplate from lying flush against the stock adaptor.

Time to test out the fitment and durability of the buffer block against the stock adaptor using the two screws. So far, looks good.

Next, a longer screw was used to secure the entire 416C stock against the stock adaptor. Note that the screw holder from the stock adaptor was used and not the one from the 416C stock.

Finally, the screw holder from the 416C stock was shortened as it was raised when placed on top of the screw holder from the stock adaptor.

The last step was to modify the lower rear pin in order to accommodate the sliding stock when it retracts. After the mod, it looked like it was CNC milled with a unique/smooth finish, so I decided to leave it unpainted.

Here is the final product, with everything secured and attached. Although it took many hours to get this far, it was worth it because it had to be perfect. Failure was not, and will not be an option for me.

Here is my current MP5K setup, ran a few hundred rounds and everything is rock solid, no wobbles nor deviations. Stock sits parallel with the body of the gun. I did not add any lights or rails, as it makes the MP5K appear too congested/futuristic which is not my preference. I preferred something simple, tactical and streamlined with a flushed top and slightly longer front end.

November 18th, 2014, 23:45	#343
turok_t Trader rating Join Date: Feb 2009 Location: Toronto, Ontario, Canada	..:::TUROK'S MP5K STOCK ADAPTOR MODIFICATION GUIDE:::. Here is a summary of the modifications in adapting the rear stock adaptor to accommodate a 416C retractable stock for the VFC MP5K. At first, the task was daunting given the number/level of difficulties and contingencies involved, but when there is a will, there is a always a way. My planning and execution had to be impeccable, not some half-assed croaked DIY that is held on by glue that ends up like a croaked broom stick. After a lot of planning here are the major steps I took. Here are the 2 items I used: Action MP5K Stock Adaptor for Marui AEG AABB HK416C style stock Note: TSC has also released Type A and Type B VFC/WE MP5K stock adaptor; however, it doesn't allow the 416C endplate sling loop to be attached. Also, these were not considered as it made the stock adaptor stick out more from the MP5K rear. Using the Action MP5K stock adaptor as the base for my rear stock adaptor, it had to be heavily modded. Given that the middle section of the rear surface is raised (look above), the 416C sling loop endplate will have a gap when placed over the stock adaptor. As such, the entire raised platform was required to be removed. I pretty much milled out this section by hand. The surface was more refined to a smooth finish, and cracks/crevices were filled with JB weld for a more even surface. You can image the degree of difficulty in removing material from around the tabs that secure the buffer tube in place, and yet it had to be completely flat for the endplate sling loop to sit flat. On the other side of the Action stock adaptor, the pin holes are housed within the raised posts as shown below. However, given the narrow size of these posts and diameter of the pin holes, there is some movement when the rear VFC pins are placed through. These were subsequently removed and grinded down. I wasn't too concerned with the overall final finishing as it would be covered up anyways. The surface was further refined and leveled to ensure that the endplate sling loop would sit completely flat against the adaptor with no gap. Next, the entire plastic VFC buffer block was removed from the PDW stock. The goal was to use this buffer block to adapt it to the stock adaptor. In order for it to fit, the entire back portion of the buffer block had to be removed. But this wasn't simple, because the entire surface needs to be completely flat and modified to just the right height. Failure to do so can cause the buffer block to sit croaked/angled against the stock adaptor, which in turn will render the 416C stock croaked as well against the main body of the gun. On the other hand, if the depth of the buffer block was too low/high, the pin holes will not align, or there will be a gap between the body of the gun and the stock adaptor. Here is a picture of the buffer block (secured by both rear pins) being test fitted for depth within the MP5K. Notice how the surface is completely flat. Now that the hard part is done, the next step was to mill a crater in the stock adaptor to accommodate the flat screw post that secures the yellow buffer in place. Here it is, the screw post sits perfectly within the crater, and lies perfectly flushed against the surface of the stock adaptor. To secure the buffer block onto the stock adaptor, I retained the original two hex screws from the buffer block, drilled two holes onto the stock adaptor and tapped threads into these holes. The two holes that were drilled above need to align perfectly with the holes on the buffer block. If I messed this up, the buffer block would not sit aligned on the stock adaptor, and hence, would mess up the alignment of the stock with the body. I had one shot to do it correctly or else everything I've done thus far goes down the drain. Here is the result. Once that was completed, the entire stock adaptor was further refined with 220, 400, 800, 1000 and 1500 grit sandpaper in preparation for airbrushing. Here is the stock adaptor after one coat of Duracoat HK black paint. Again, wasn't too concerned with the finish as it would be concealed at the end, but nonetheless, not bad. After the painting, the two screws that secured the buffer block on the stock adaptor were shortened so they were flushed against the stock adaptor. Again, if the two screws were protruding, it would block the sling loop endplate from lying flush against the stock adaptor. Time to test out the fitment and durability of the buffer block against the stock adaptor using the two screws. So far, looks good. Next, a longer screw was used to secure the entire 416C stock against the stock adaptor. Note that the screw holder from the stock adaptor was used and not the one from the 416C stock. Finally, the screw holder from the 416C stock was shortened as it was raised when placed on top of the screw holder from the stock adaptor. The last step was to modify the lower rear pin in order to accommodate the sliding stock when it retracts. After the mod, it looked like it was CNC milled with a unique/smooth finish, so I decided to leave it unpainted. Here is the final product, with everything secured and attached. Although it took many hours to get this far, it was worth it because it had to be perfect. Failure was not, and will not be an option for me. Here is my current MP5K setup, ran a few hundred rounds and everything is rock solid, no wobbles nor deviations. Stock sits parallel with the body of the gun. I did not add any lights or rails, as it makes the MP5K appear too congested/futuristic which is not my preference. I preferred something simple, tactical and streamlined with a flushed top and slightly longer front end. Last edited by turok_t; October 6th, 2017 at 21:29..