Troubleshooting STEN Mk.5 with Glock mag conversion

[Walkingfunk]

Hello!
I am currently working on a Sten mk5 kit with Indianapolis ordnance semi auto conversion parts and a modified mag well that accepts Glock magazines.

first things first. I don’t take credit for the Glock magwell, it was designed by Will_it_print on Reddit for a Sten Mk2 and he has posted his later second version of it for free open source download, it is his second version that I am trying to use.

https://www.google.com/amp/s/amp.reddit.com/r/DIYGuns/comments/br5qo7/mkii_sten_mag_adapter/
https://www.google.com/amp/s/amp.reddit.com/r/DIYGuns/comments/br5qo7/mkii_sten_mag_adapter/
https://imgur.com/a/GFjeiN3

That all being said and giving credit to where it is due....
This thing is giving me some major issues and I think it’s gonna be a bit different by the time I’m done..

First off. The mag angle is perfect but it locks in too deep. The bolt hits the magazine instead of stripping off a round. If I pull the mag out a bit then it functions fine. So I need to find a way to alter the magazine well (of essentially a Glock gen 3). I put a piece of tape at the correct feeding depth and drew a pencil line at the locking depth to figure out that it needs to lock into place 1/8” further out.
I do not want to alter the magazines to fix this problem unless I have no other option because that kinda defeats the purpose of a sten that takes Glock mags and makes it into a sten that needs modified magazines.

The second problem that I have is that I went ahead and cut the receiver tube blank as instructed and when I put my custom magwell on it the feeding and rejecting ports don’t line up. I need to put the mag hole in the tube further down because it’s not as “in-line” as the original 90 degree sten magwell. If I scootch it over so it feeds okay then the ejection port is not longer centered right (and i feel like the original creator would have figured that out right??)
The simplest solution I see now is to make the feeding work and cut the ejection port and then put a vertical pin through the wasted negative space and fashion a buckle-silver plate to fix any balance/aesthetic issues afterwords.

My plans are to make this sten and then have the pla magwell cast out of bronze to make a more permanent piece as well as an homage to the sten’s predecessor the lanchester smg.
There is an integral picitinny rail in the magwell for an optics, but my hope is that the Glock mag and optic will make this gun more fun and reliable, while the overall construction of the gun will still be steel, wood, and bronze. That way it won’t look TOTALLY gross.

When I am totally done, I want to potentially due a full etching on every single part of the gun to give it a classier metalworker look (since it’s mine and I want it to reflect my personality). I also want to replace the round charging handle with a bronze charging handle to give the design more cohesion in materials as well as make it a smidge longer and give it the shape of a mp18 charging handle.

I’m hoping this piece will help me get jobs in the future as an example of my work. I will attach pictures of what I’m talking about and stuff. I can add more pictures later too. Thanks for reading this really long post.
-Dante

 

[Walkingfunk]

I kept futzing with my magwell and it seems like the original designer of the piece had everything correct, I was the one who had it improperly orientated.

Now after a bunch of filing and getting things together, my optional safety only works half of the time, but I think it’s cause the top and bottom aren’t welded together yet and it keeps flopping around.

My current problem is that the linear hammer/striker block is encountering resistance and stopping before hitting the firing pin. My guide rods are welded together on that washer thing in the back, and rereading carefully I may have messed up the angle and the instructions said to peen the ends, so I will remake this part and hopefully it’s the welded ends restricting the movement of the bolt/striker, and my remade parts will work and I can finally weld up. Then it’s just waiting for my bronze magwell to finally come.

 

[Walkingfunk]

Not sure if anyone is actually reading this thread, but if this can help someone else later who is trying to do the same thing...

This is my first real gun build (let’s be real, ARs don’t count!), but hopefully if anyone has questions I can answer them now.

 

[BBBBill]

Well, I'm reading, but I have no experience with the Sten and nothing to offer other than "Good Luck and hope you succeed!"

 

[milsurpguy]

I figure you could effectively and cheaply buy a sten mag well, chop it up then cut, bend and weld it up to fit potentially any mag you can think of. Brass might look kind of cool.
I would like to make a sten mag well take Stirling mags.

 

[Walkingfunk]

Most of the cost of casting was for the initial setup so I was quoted for 210 dollars for one, but if I ordered 12 they were only 88 dollars each.
I ended up ordering 3.
So I should have two spares when I’m done in case I mess up or wanna make another eventually.

 

[Walkingfunk]

I’m so tired of the dual spring crappy system from the IO kit. I’m going rogue and cutting the lower housing to bits and I’m going to shove a 4lb velocity ar-15 trigger in it. I’m also going to change it to use the original one larger spring rather than the two smaller springs.
The scratched lines are where I am going to cut it.
New spacer type deal will use old hole to push big spring further back and allow access to a slo

 

[Prerunner1469]

i have a few questions do you have any update for the build?

how did you make the mold for the glock mag, did you 3d print it or pay someone to 3d print it?

did you get the mag adapter casted like you wanted to also?

if so do you have anyway you can help me i dont have a 3d printer and i would pay you for a 3d printed one so i can get it casted

 

[Prerunner1469]

also with the with the lower ar trigger i see you bought the semi auto bolt and seem to have been modifying it to make it use the original bolt spring with a slot for the ar hammer to go into and strike the firing pin so you dont have issues with firing and keep it more like a complete bolt? am i correct?

 

[Walkingfunk]

Sorry for the late response, I have been on the Appalachian Trail for the past two months. Hiked 730 miles from Georgia into Virginia.

I originally used the open source file and printed it with a friend’s printer out of PLA plastic filament with the original intention of doing a pla burnout casting at my house with a kiln that I have. However I kinda wanted this as a sort of portfolio piece and sprung for a professional casting service to make the part for me. When searching for companies I started with prototyping companies and metal 3D printing companies and I was met with either refusals due to it being a firearm component or outrageous quotes into the thousands. So I switched gears, i once got a gun part tig welded cheaply and well by going to a motorcycle welder,
So I figured a sculpture company would be able to do it as well…
I ended up going with a west coast company called Firebird Bronze. I had to email the atf and get a letter that this magazine housing was okay for them to make because they were dubious at first, but I ended up getting the part a few months later. I ended up getting a casting tree made with 3 bronze magwells. One of the three castings doesn't look as usable as the others and will probably be a display. I purposefully asked for the raw casting without any finishing work in order to keep the price down.

Also, yes, I assembled the semi auto kit and it just didn’t really work right and it just sort of clicked in my mind that I could use the original spring and alter the semi auto bolt as you said.

 

[Walkingfunk]

 

[Walkingfunk]

I kind of want to hold on to all three of my bronze castings cause one I want to use as a sample, one I want to use on my build right now, and I want to build a more historically accurate version one day in regards to the ar trigger (which is going to totally change the lines of the gun).
I might have an extra plastic one however. PM me.

 

[Prerunner1469]

thank you for the update yes i would like to get the plastic one i will pm you!

 

[Prerunner1469]

also please continue to post on how you are doing the ar trigger and build