GSG 16 airsoft cocking tube mod Picture Heavy

jhedsy

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I decided since it is so difficult to find a conversion kit solely for the front sight mp5 look that everyone wants, I would try and fit an airsoft cocking tube to my GSG-16. The end result after a couple hours or fine tuning and fitment, it works! I considered posting this in the GSG-16 modification thread, but I had too many pictures that I wanted to post.

The part I used was an ICS MP5/MX5 Aluminium Cocking Tube & Handle. Part #MP-27. Hopfully this will open up some doors to those who like to tinker and mod. For tools, I used a basic drill press, a die grinder, and some sandpaper. Note: If you do this, do it at your own risk.

It's near identical the the conversion kit tube with a few minor differences. The protrusion along the bottom seen in the pictures needs to be cut off or trimmed so it does not interfere with the barrel, the front hole for the barrel has to be drilled out to the correct size, and the inside of the tube needs to be sanded till the charging bolt slides freely back and forth without getting jammed inside. I decided not to mess with the steel charging bolt itself due to the fact that if I wanted to put it back to OEM, I can. The charging handle needs to be used with the slide because the opening on the airsoft tube is to narrow for the GSG-16 handle unfortunately. However, everything functions as it should and handles are cheap and available should one break.

And now for the pictures! I have the original gsg-16 conversion tube next the the airsoft one for comparison. I will try to keep them in order best I can.





Below: To get the steel cylinder to slide inside the tube without jamming, you will need to sand out the inside of the tube.
This was the most lengthy part of the whole process. Pictures of the sanding progress are further down in the post.
This picture shows as far as it would slide inside.














































Below: The GSG handle will not fit unless you modify the handle, widen the opening, or use the smaller airsoft one supplied from ICS.
I used the smaller ICS handle.










And last but not least, the Dlask thread adapter screws on with no issues. I'm sure there would be no issue with the faux suppressor either.
 
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Nice job Jhedsy!
I gave up on the ICS due to the inside tube dia for the charging handle being too small. Nice work getting it to fit!!

The biggest problem with the non GSG MP5 charging tubes is the center spacing from center of charging tube to center of barrel. Every airsoft I tried are wider than the GSG model. The barrel shaft on the cocking tube assembly must be drilled offset from CL for proper alignment. If the alignment isnt perfect you will have binding of the charging handle and upward pressure on the barrel changing point of impact with the rifle.

The GSG 522 was based on a very early GSG airsoft MP5 that had dimensions different then most modern Airsoft.

This mod is definitely doable as shown, but be aware that you need to get the cocking tube perfect with the barrel. If you get minor sticking of the charging handle after assembly, the problem is the barrel is not in proper alignment and will need further adjustment. If you oversize the hole then the barrel wont have proper support either. This is the most finicky part of the mod
 
Nice job Jhedsy!
I gave up on the ICS due to the inside tube dia for the charging handle being too small. Nice work getting it to fit!!

The biggest problem with the non GSG MP5 charging tubes is the center spacing from center of charging tube to center of barrel. Every airsoft I tried are wider than the GSG model. The barrel shaft on the cocking tube assembly must be drilled offset from CL for proper alignment. If the alignment isnt perfect you will have binding of the charging handle and upward pressure on the barrel changing point of impact with the rifle.

The GSG 522 was based on a very early GSG airsoft MP5 that had dimensions different then most modern Airsoft.

This mod is definitely doable as shown, but be aware that you need to get the cocking tube perfect with the barrel. If you get minor sticking of the charging handle after assembly, the problem is the barrel is not in proper alignment and will need further adjustment. If you oversize the hole then the barrel wont have proper support either. This is the most finicky part of the mod

I decided to use the GSG-16 inside steel tube piece because the plastic airsoft one is too small. I had to sand the heck out of the inside of the outer tube for it to even fit. Once I got it to fit, I would cycle it and it would jam because I didn't sand far enough down into the tube, back to sanding! Now it fits perfect and cycles every time even using the mp5 slap.

As for the hole for the barrel, I used the existing smaller airsoft barrel holes as a guide. I used a 1/2" drill bit as thats all I had. 1/2" = 12.7mm. Barrel is 12mm. Close enough for me. I don't force stuff if it doesn't fit, thats how you break things lol. Most of it is just patience and head scratching.
 
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Awesome solution! Maybe the ICS is the same barrel to cocking tube spacing. I'll check the measurements with the one I purchased. The airsoft cocking assembly unit I ended up using fit the GSG steel charging tube but not the barrel.

I'll post up my mods as well since I have a different version
Great thread Jhedsy!

If you want to use the GSG16 charging handle you just need to file down the top and bottom of the steel shaft. That what HK does so it must be ok lol.

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Awesome solution! Maybe the ICS is the same barrel to cocking tube spacing. I'll check the measurements with the one I purchased. The airsoft cocking assembly unit I ended up using fit the GSG steel charging tube but not the barrel.

I'll post up my mods as well since I have a different version
Great thread Jhedsy!

The barrel to cocking tube is pretty darn close to the GSG16 one, I'll have to measure it with my micrometer. I wouldn't think it's bang on perfect but honestly I eyeballed it. That 0.7mm from using a 1/2" bit that I used might even have something to do with it.

I'm interested to see your mods and what you've done!
 
If you want to use the GSG16 charging handle you just need to file down the top and bottom of the steel shaft. That what HK does so it must be ok lol.

I considered it but the stock OEM ones break evening without modding them. I may consider a machined aftermarket one if or when I break this one then modding it with a file. It would be better that the pot metal airsoft ones for sure.
 
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