Third Party Press

MP38L Build

Kintepro

Kintepro

Well-known member
This is a project I'm just starting to work on and wanted to share some progress. I've finished modeling the receiver pieces. I still have a long list of to-do items, but I thought you guys would find this interesting. The internals will be designed to use the Indianapolis Ordnance MP40 semi-auto kit.

I always thought the mp38L was pretty cool and certainly impossible to obtain an original one. I see SSD has made at least one, though it was milled out of solid aluminum - which is way beyond my capability. I can, however, cast metal. So, that's what I'm gonna take a stab at with this project.

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I'll have to give the free trial a try. Keep us updated on the project, This might be a fun thing to try 3d printing (maybe not a working model).
 
RacketyTurnip said:
I'll have to give the free trial a try. Keep us updated on the project, This might be a fun thing to try 3d printing (maybe not a working model).
Click to expand...
That's the plan currently. I think I will be able to 3D print a model that will at least functionally cycle dummy rounds (not fire though). Eventually I'll use a lost PLA plaster casting for the aluminum receiver. That model will have to be modified though, as there is no way I can cast with all of the cutout features and holes. I am just hoping I can get close enough and dremel the rest without needing a mill.
 
I am close to completing the first iteration of the model... I just need to flesh out the design for the fire control group and do some spring calcs to make sure the trigger pull isn't going to be too bad. I think I'm going to run into the same problem that TNW did with their early striker fired Suomi M31's. The Indianapolis Ordnance bolt is a striker design, not a rotating hammer, and the sear has to push the striker back some before firing which adds force to the trigger mechanism.

I picked up a barrel, stock, and some mags from dk/ssd as well.

In the mean time, I am starting to print the parts that I can for the mock up. The barrel nut below is solid PLA+ and took 12 hours. I just finished fitting it today. I still need to tap the threads and I am waiting on a bigger tap handle for these monstrous M36 taps.
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I had to file down the aluminum resting bar to fit. It looks like the original (on the right, pic from forgottenweapons.com) had a similar flat end shape in order to clear the larger barrel nut.
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First mockup is printed. I realized that I have some fitment issues from printing lengthwise. This increases strength but reduces fidelity due to warping and drooping off supports... I may have to re-print vertically and tune my printer a bit for better fidelity so that all of the components function smoothly.

I also am struggling with getting the bolt and extractor to grab dummy rounds. It will push them in the chamber, but the extractor from Indianapolis Ordnance fits so tightly that it never wants to engage the casing. I may try bending it to various degrees and see what works.


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This is a fantastic piece of work. Most of it made with a printer? I notice different color materials. Are these different strength/composition plastics that can be used by the printer? ( I am not very knowledgeable about these printers).
I just purchased an Indianapolis Ordinance 1928A1 BFONG upper to finish a mint Russian parts kit I’ve had for years. It runs like a clock. They also do some nice work.
 
biggymu said:
This is a fantastic piece of work. Most of it made with a printer? I notice different color materials. Are these different strength/composition plastics that can be used by the printer? ( I am not very knowledgeable about these printers).
I just purchased an Indianapolis Ordinance 1928A1 BFONG upper to finish a mint Russian parts kit I’ve had for years. It runs like a clock. They also do some nice work.
Click to expand...
All of the printed parts are just PLA+. The barrel nut and some of the small parts are a black color while the whole receiver is grey. It simply appears to be different shades of grey due to the lighting. Surfaces have different levels of sheen depending on which direction they were printed.

I reprinted the nut because I messed the threads up. It's harder to thread straight in plastic than I though... they really want to veer off axis. Added a very large chamfer to guide the tap in when I did the second nut (the black one you see in the most recent post).

Yea IO seems to make good stuff, I think the problem with the extractor is on my end. Either I didn't install it correctly or I need to adust the placement of the magazine/barrel.
 
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