b-wingpilot
CGN Regular
- Location
- Sherwood Park
Creating this thread as a reference/tutorial for those that want some cosmetic upgrades for their GSG-16. So, if you want to build something like this, please follow the steps below:
Parts list:
GSG-16 rifle
GSG-5 conversion kit
G&G retractable MP5 stock, (CYMA fixed or retractable stock will work to)
G&G MP5 handguard with light
MP5 or G3 rear sight
HK receiver pins - small
Dlask 9” barrel or a .22lr barrel blank
1/2 x 28tpi trilug mount
4-48 x 0.25” machine screws
Materials:
0.625” OD 0.083” Wall 4130 steel tubing
0.5”OD copper bar
0.125”x0.5” 1018 steel bar
0.25” 1018 steel bar
Paint
Sandpaper
Tools:
Lathe - can substitute with a drill press and a file if you’re “Dara” enough
Milling machine - again, can substitute with a drill press if you have skills that belong in Dara Adam Khel
TIG welder
Coping saw / dremel / file
Some good files
Sand paper
4-48 tap
M16x1 die if you can’t do metric threads on your lathe
Skill level required:
Moderate - Advanced. This build is definitely not for a beginner, but I HIGHLY encourage that anyone that wants to do this type of conversion to go for it. This is a great rifle to start learning some skills on. It is relatively cheap and it is still available for retail sale. That said, the more difficult things may turn into off-the-shelf purchasable items. Dlask is making a 9” barrel, so one doesn’t have to machine one up from a blank. I’m looking at having the top rail 3D printed in Nylon 6-6 so it will just be a drop in item. Also looking at having the trilug machined complete instead of modifying an existing MP5 trilug.
Disclaimer:
I am not claiming I be an expert or that this is the best way to accomplish the end results. Others may have better ideas / methods.
Anyway, on to the build!
Not going to show complete disassembly or the conversion kit installation as there are lots of threads and videos out there on how to do it. So we’ll just skip ahead to what needs to be done:
1st step, rail removal. With the receiver in two halves start removing the rail “boss”. Use I coping saw or dremel to remove the bulk of the plastic seen here (right half removed boss, left half untouched):
Then with the bulk of the plastic removed, use a file to shape it to the round profile of the receiver so it ends up something like this:
Finally, finish up with increasing grits of sandpaper to blend everything.
2nd step, removing the ribs on the magwell. Again you can use a dremel to remove the bulk of material, then on to the file and sandpaper to blend. Should end up looking like this:
3rd step, fitting the MP5/G3 rear sight. Use a good file and go slow, constantly checking the fit. You will use the existing “boss” and threaded hole, so make sure it is centered with the ovaled hole in the rear sight. Should look like this when complete:
4th step, top rail. This step took quite a long time to fabricate out of steel. Used 2 different pieces, then welded them together. Start with the 0.5” wide bar and mill or dremel to fit. Then use a smaller piece of barstock to mill out the “notched” part of the rail. Once complete weld them together. Mark the locations for the existing holes from the top of the receiver on the newly made top rail. Drill and chamfer for tapered 4-48 machine screws.
5th step, make the rail nuts. Copy external dimensions of the factory brass nuts in some steel barstock, or I suppose other materials could be used. Note that they are not completely round and have flats on the side to fit into the oval shaped holes of the top of the receiver. Then drill and tap for 4-48 bolts.
6th step, machine the barrel from a blank or install a dlask barrel. I’d reccomend going with a dlask barrel. I machined one from a blank and it was a huge pain. Going from 1.5”OD to 0.47”OD wasn’t fun on a manual lathe. Plus removing the factory barrel wasn’t a picnic and required a mandrel and a press.
7th step, weld or pin the retractable stock in the open position. I made a blocking piece from steel barstock and welded it to the stock so that it could not be collapsed anymore. I wouldn’t reccomend the way I did it as the excessive heat melted the plastic a bit.
8th step, buttstock fitment. Once the receiver is assembled with the conversion kit, then you can start to fit the stock to the receiver. The G&P stock had to be cut and filed a bit to fit. Use the included pushpin for assembly.
9th step, modify the trilug. Open up the ID of the 4130 tubing to fit the OD of your barrel (0.47 if I remember right). Then thread the outside to M16x1 using a lathe or an M16x1 die will work too. It only needs to be about 0.4” long. Then machine a copper backing bar to the same OD as your barrel. Next it’s time to weld your threaded tube to an existing 1/2x28 MP5 trilug.
Last step is to paint your receiver, top rail and trilug. Cerakote is best, but not required.
Now assemble it all and enjoy
Parts list:
GSG-16 rifle
GSG-5 conversion kit
G&G retractable MP5 stock, (CYMA fixed or retractable stock will work to)
G&G MP5 handguard with light
MP5 or G3 rear sight
HK receiver pins - small
Dlask 9” barrel or a .22lr barrel blank
1/2 x 28tpi trilug mount
4-48 x 0.25” machine screws
Materials:
0.625” OD 0.083” Wall 4130 steel tubing
0.5”OD copper bar
0.125”x0.5” 1018 steel bar
0.25” 1018 steel bar
Paint
Sandpaper
Tools:
Lathe - can substitute with a drill press and a file if you’re “Dara” enough
Milling machine - again, can substitute with a drill press if you have skills that belong in Dara Adam Khel
TIG welder
Coping saw / dremel / file
Some good files
Sand paper
4-48 tap
M16x1 die if you can’t do metric threads on your lathe
Skill level required:
Moderate - Advanced. This build is definitely not for a beginner, but I HIGHLY encourage that anyone that wants to do this type of conversion to go for it. This is a great rifle to start learning some skills on. It is relatively cheap and it is still available for retail sale. That said, the more difficult things may turn into off-the-shelf purchasable items. Dlask is making a 9” barrel, so one doesn’t have to machine one up from a blank. I’m looking at having the top rail 3D printed in Nylon 6-6 so it will just be a drop in item. Also looking at having the trilug machined complete instead of modifying an existing MP5 trilug.
Disclaimer:
I am not claiming I be an expert or that this is the best way to accomplish the end results. Others may have better ideas / methods.
Anyway, on to the build!
Not going to show complete disassembly or the conversion kit installation as there are lots of threads and videos out there on how to do it. So we’ll just skip ahead to what needs to be done:
1st step, rail removal. With the receiver in two halves start removing the rail “boss”. Use I coping saw or dremel to remove the bulk of the plastic seen here (right half removed boss, left half untouched):
Then with the bulk of the plastic removed, use a file to shape it to the round profile of the receiver so it ends up something like this:
Finally, finish up with increasing grits of sandpaper to blend everything.
2nd step, removing the ribs on the magwell. Again you can use a dremel to remove the bulk of material, then on to the file and sandpaper to blend. Should end up looking like this:
3rd step, fitting the MP5/G3 rear sight. Use a good file and go slow, constantly checking the fit. You will use the existing “boss” and threaded hole, so make sure it is centered with the ovaled hole in the rear sight. Should look like this when complete:
4th step, top rail. This step took quite a long time to fabricate out of steel. Used 2 different pieces, then welded them together. Start with the 0.5” wide bar and mill or dremel to fit. Then use a smaller piece of barstock to mill out the “notched” part of the rail. Once complete weld them together. Mark the locations for the existing holes from the top of the receiver on the newly made top rail. Drill and chamfer for tapered 4-48 machine screws.
5th step, make the rail nuts. Copy external dimensions of the factory brass nuts in some steel barstock, or I suppose other materials could be used. Note that they are not completely round and have flats on the side to fit into the oval shaped holes of the top of the receiver. Then drill and tap for 4-48 bolts.
6th step, machine the barrel from a blank or install a dlask barrel. I’d reccomend going with a dlask barrel. I machined one from a blank and it was a huge pain. Going from 1.5”OD to 0.47”OD wasn’t fun on a manual lathe. Plus removing the factory barrel wasn’t a picnic and required a mandrel and a press.
7th step, weld or pin the retractable stock in the open position. I made a blocking piece from steel barstock and welded it to the stock so that it could not be collapsed anymore. I wouldn’t reccomend the way I did it as the excessive heat melted the plastic a bit.
8th step, buttstock fitment. Once the receiver is assembled with the conversion kit, then you can start to fit the stock to the receiver. The G&P stock had to be cut and filed a bit to fit. Use the included pushpin for assembly.
9th step, modify the trilug. Open up the ID of the 4130 tubing to fit the OD of your barrel (0.47 if I remember right). Then thread the outside to M16x1 using a lathe or an M16x1 die will work too. It only needs to be about 0.4” long. Then machine a copper backing bar to the same OD as your barrel. Next it’s time to weld your threaded tube to an existing 1/2x28 MP5 trilug.
Last step is to paint your receiver, top rail and trilug. Cerakote is best, but not required.
Now assemble it all and enjoy
Last edited:
