Building a Suomi Thompson carbine (from http://www.weaponeer.net/forum/printer_friendly_posts.asp?FID=232&TID=6885 )
Building a Suomi Thompson Printed From: Weaponeer.net Forum Name: Home Build Projects Forum Discription: Post your projects here URL: http://www.weaponeer.net//forum//forum_posts.asp?TID=6885 Printed Date: June 12 2016 at 12:11pm Topic: Building a Suomi Thompson Posted By: gundoctor Subject: Building a Suomi Thompson Date Posted: April 06 2008 at 12:15pm I've watched the enormous amount of effort that has gone into building the Suomi. I guess I'm a little different than most people in that I tend to buy a lot of parts instead of kits, and I tend to buy parts kits to get the parts not the kits. I like the suomi because the kit comes with 1 part that is worth the price of the kit: a very good chambered 9mm Swedish barrel. Plus a drum magazine. Plus a recoil spring. Plus enough stuff left over to build a dummy gun or something exotic out of the barrel shroud. I've always wanted a Thompson, but I let kits get out of sight before I bought one, and a build not only requires an expensive kit, but also an expensive receiver. Why not a "suomi thompson"? Basics: 1. 2. 3. 4.
Use Use Use Use
Suomi barrel, bolt, recoil spring, and magazines Thompson Wood (available and fairly cheap) AR-15 FCG an easily built tube reciever
I'm not trying to reproduce an authentic version of anything, simply adding another shooter to my collection.
Replies: Posted By: gundoctor Date Posted: April 06 2008 at 12:19pm Well, I'll start with the barrel. Turn it down into a little bit of a taper. Needed to add some length to get 16"--so I did so with some 1" rod which I welded on the barrel. I then shaped this into a "compensator" which will keep the finished product from looking too long. I simply bored out the "compensator" and cut some slots across it with a small endmilll.
------------Fraternitas in Armum ™
Posted By: gundoctor Date Posted: April 06 2008 at 12:24pm
Next, I need a bolt.
Top: original Suomi bolt. Middle: pieces prepared for new bolt. Bottom: cut off / discarded part of suomi bolt. I stripped the suomi bolt and cut if off with a chop saw. Prepared it for a AR15 firing pin setup. And turned the rear portion down to 7/8". Then I used a piece of square stock to make the bolt body. It was center drilled for the recoil spring and slotted to clear the hammer. Then the front was drilled 7/8" to accept the cut off suomi bolt. I used an endmill to drill this hole the final diameter so it would be flat bottomed.
Posted By: gundoctor Date Posted: April 06 2008 at 12:27pm Here are some mock ups. They also show the lower receiver, which I cut out of aluminum bar scrap. I bought a 1 3/4" end mill for $20 which made the radiuses for the pistol grip and just behind it. It is set up for the AR15 FCG. I built this prototype out of aluminum for
"ease", but intend to make the final version in steel so I can blue it.
------------Fraternitas in Armum ™
Posted By: gundoctor Date Posted: April 06 2008 at 12:30pm The following shows my roughed out receiver.
It is simply a piece of mild steel square tubing.
------------Fraternitas in Armum ™
Posted By: Guests Date Posted: April 06 2008 at 12:33pm WOW... -------------
Posted By: dcorb Date Posted: April 06 2008 at 12:40pm
I edited a couple of the posts to reduce the page width. Very impressive build. I think I now know what I am going to use one of Soumi kits for.
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Posted By: gundoctor Date Posted: April 06 2008 at 12:42pm Thanks Decorb for cleaning up the post.
I don't know why they came out in those crazy proportions.
Posted By: weaponeer Date Posted: April 06 2008 at 2:04pm Very good idea! it's looking great... ------------Weaponeer.net survives on donations made each Month by the membership. if we don't get enough donations, our hosting provider turns off the website, and only turns it back on after the hosting fee's have been paid. Please... every donation counts
Posted By: TbcSEOD Date Posted: April 06 2008 at 2:40pm Thats very cool indeed! ~TbcSEOD -------------
Posted By: Nitegunner
Date Posted: April 06 2008 at 4:33pm gundoctor wrote: The following shows my roughed out receiver.
It is simply a piece of mild steel square tubing.
What are you using here in this picture for the trunnion? I can see the front part of the feed ramp, but how is this all going to come together? ------------Nitegunner Keep legal, stay free & support our 2nd Amendment
Posted By: gundoctor Date Posted: April 06 2008 at 5:01pm The trunnion is a combination of things: some of the old trunnion and some bar stock. I'll show how to make one later, but I made this one up without taking any pictures. I did use the original suomi forward mag well and feed ramp which detach from the front filler--which is what
you recognized. To keep the lines of the original thompson the barrel bore would not be centered but near the top of the receiver, and I might change that before I finish the build. I am showing the prototyping as it occurs to stimulate discussion and interest. I have considered having a new trunnion / forward receiver investment cast is there is enough interest in the build by others.
Posted By: rocco1911 Date Posted: April 06 2008 at 5:05pm WOW this is nice I'm interested hope your documenting it all so you can put it on a disc I would buy one with all the Suomi kits out there this is a great alternative you have skills there buddy.
Posted By: USMCsean8531 Date Posted: April 06 2008 at 6:33pm One thing that would help, when comparing with the Suomi bolt, is to not have the hole that accepts the spring, to not be drilled all the way through to the area with the new floating firing pin goes. ie; where you slotted your new bolt for the hammer setup. That way, you could use the springs in the same manner in which they were intended. Unlike in our semi auto Suomis we have to fix the recoil spring problem, which some people have done with Sten recoil springs. ------------Semper Fi, Sean "If people don't kill people, but guns do kill people; Does that mean I can blame my pen for the mistakes that I make when Im writing?"
Posted By: gundoctor Date Posted: April 06 2008 at 7:44pm Marine Sean, your idea is sound if you leave the bolt 2 piece. But, if I make it one piece I will have to have a way to get the firing pin out, which means the hole must be accessable to remove the firing pin. I intend to use "weld capture" to attach the front of the suomi bolt to my bolt body. I will show that later. I will use a cross pin (behind the hammer cut out) to allow the recoil spring to bear against and not intrude into the hammer space. By removing this pin I can back the firing
pin out the back of the bolt if needed. Hope this makes sense. That said, your idea is workable if you leave the bolt head removable to access the firing pin.
Maybe I'll build it that way.
Doc
Posted By: tommerr Date Posted: April 06 2008 at 7:55pm You are being watched. ------------Tommerr
Posted By: gundoctor Date Posted: April 06 2008 at 8:03pm Tommerr. Is "being watched" a good or a bad thing?
Should I sleep with the CETME45K under the pillow at night?
Posted By: Nitegunner Date Posted: April 06 2008 at 8:38pm gundoctor wrote: Tommerr. Is "being watched" a good or a bad thing?
Should I sleep with the CETME45K under the pillow at night?
No.. this is very interesting. You are going to have a lot of people watching this one. ------------Nitegunner Keep legal, stay free & support our 2nd Amendment
Posted By: USMCsean8531
Date Posted: April 06 2008 at 9:31pm gundoctor wrote: I will use a cross pin (behind the hammer cut out) to allow the recoil spring to bear against and not intrude into the hammer space. By removing this pin I can back the firing pin out the back of the bolt if needed. Exactly! That was what I was trying to get at, but not as elegantly described. When I meant not drilled through, I was meaning the area where the horizontal hole for the spring and the vertical milled slot for the firing pin are located. So these two features do not touch. Which is where you said you would put a pin for the spring to bare against.
------------Semper Fi, Sean "If people don't kill people, but guns do kill people; Does that mean I can blame my pen for the mistakes that I make when Im writing?"
Posted By: tommerr Date Posted: April 07 2008 at 12:05am
This shows my firing pin retainer hole. They are real buggers to drill. I built a drill fixture and it has a drill bushing on the top and bottom. Because I am drilling into a hole, I have to drill from both sides or the drill would shatter. Hi Roc drills are expensive. I destroyed five drills doing seven bolts. That was a painful lesson. I drill to the center of the firing pin hole and then stop. ------------Tommerr
Posted By: gundoctor
Date Posted: April 07 2008 at 2:00am Marine Sean: I might not end up using the original suomi spring in the center hole. I built a suomi bolt with an off center hole to utilize a Mac 11 type spring / guide rod set up. I never built up a receiver for it but this concept might work in some of the designs you are talking about. It would allow you to get a little more spring length into play if you need too. Attached are a couple of pix.
The bolt is discolored because I annealed it before drilling, intending to reharden and polish it later. That is a M11 9mm recoil spring. This would also be a good setup to use if you want to do a striker fired build as you would use another spring in the middle for your striker.
Posted By: gundoctor Date Posted: April 07 2008 at 2:12am Another modified suomi bolt. This one was squared up and slotted for an AR Hammer. Fits a square tube build, but too small to look proportional on the Thompson. Just giving away ideas for those of you trying to figure out what to do with those suomi kits. Doc
Posted By: gundoctor Date Posted: April 10 2008 at 12:00am Here are some pix of the trunnion. Story on trunnion. This is the front part of a receiver I built to use the 1" square suomi bolt shown in an earlier picture. Didn't really like it so I cut off the front of this receiver and will now use it as a "trunnion" to slip in a larger piece of square tubing to make the suomi thompson.
The original suomi front receiver pieces were rewelded usiing an internal steel mandrel, and then squared to 1". The lugged front of the trunnion was turned down round, and a piece of 1" square stock was drilled to slide over it and welded to the receiver shoulder and front of the trunnion. I then drilled out the mandrel (which of course was welded to the receiver in the reweld process. This prevented it from ever being contraband. The entire assembly was then slipped partway into a piece of 1 1/4" x .120 wall square tubing (i.e. the receiver tube for the original gun with a 1" square bolt) and welded all around, including the cut outs for the original mag well and ejection port. Another piece of 1" sq stock was then grooved and welded to the front to provide a place for the forend mounting bar and support for the original feed ramp / forward mag well which was removed from the suomi front filler. I shaped it to please my eye. This assembly will now slide into the 1 1/2" x .120 wall tubing (i.e. 1 1/4" bolt size) that will be the suomi thompson receiver. It will then be
welded all around, including the ejection port and mag well. A lot of trouble, and not the best but this is just prototyping by picking up stuff on the workbench and figuring out how to make it work and look like I wanted. I think I will mill the top of the trunnion to keep the receiver topline straight before assembly (will require a new bolt body to keep the bolt head centered with the bore).
Posted By: tommerr Date Posted: April 10 2008 at 7:04am I wish to provide some input on welding and heat treating. If you weld on hardened steel, please, immediately, stress relieve the part at 400F, at temperature, for one hour. The problem is stress cracking. If you decide to anneal a Suomi bolt, I will investigate re-heat treating instuctions. I will analyze the steel chemistry of the Suomi bolt and get some hardening recommendations. Safety for my friends is important. ------------Tommerr
Posted By: gundoctor Date Posted: April 10 2008 at 7:58am
Tomerr, the chemistry would help on the bolts to allow more flexibility in working with them if they can be safely annealled and rehardened. Testing steels for chemistry is out of my purview. I did not anneal the bolt for the suomi thompson. I cut it with a cut off saw (abrasive) with a wet rag around the bolt head. I then used the lathe to face the rear of the cut off bolt head. This is the same way that I cut and reweld mauser bolts and receivers to shorten them without changing the heat treatment in the critical areas (receiver ring and locking lugs of bolt). I do not intend to weld on the bolt head, but planned to use some short pins that are inserted through the bolt body into it--these pins will then be welded over (but the welding will be pin / bolt body, not to the bolt head. This will "capture" the bolt head in the bolt body. In this way I hope to maintain the intergrity of the suomi bolt head and its heat treatment. These pins will not take the force of recoil, as that will be borne by the shoulder in the bolt body. As an alternative, I am considering leaving the bolt two piece and using a single cross pin to both retain the bolt head to bolt body and the firing pin. I've welded on the receiver pieces a good bit, and my guess is that these are mild steel in that they weld very good with none of the spitting and brittleness usually associated with higher carbon steels.
Posted By: gundoctor Date Posted: April 13 2008 at 1:19am Update: Only got to work a few hours--and the mig ran out of gas and the autodim helmet went caput--but I manged to get the trunnion roughed in. Used the original suomi ejector but was tempted to fashion one like the Thompson--simple, easy to make design. In reshaping the trunnion front I've milled through the weld attaching the lower piece, but I'll grind that out and reweld once I can get some gas. Bolt is working and clearing the mag lips---I think this thing will run if I get the lower finished and attached. Still thinking of some novel ways to attach the lower, buttstock and rear cap (think I can "integrate" this)--and even include the rear sight base in the equation. This one's not perfect but the first one never is. I don't try to make the prototypes perfect--I plan and measure but don't try to make cosmetically perfect as I know it will probably change or have to be redone.
Posted By: weaponeer Date Posted: April 13 2008 at 1:34am Very nice progress ------------Weaponeer.net survives on donations made each Month by the membership. if we don't get enough donations, our hosting provider turns off the website, and only turns it back on after the hosting fee's have been paid. Please... every donation counts
Posted By: Inabadhood Date Posted: April 14 2008 at 10:26am VERY nice progress, Indeed! Looks like it's coming together beautifully!
Posted By: gundoctor Date Posted: April 17 2008 at 9:15pm Update: Worked on the bolt body and a foreend mount. Did the design for the end cap and a couple of potential ones on the mag catch. Finishing the lower is going to require a 14 x 24 tap--an odd size but used for the Thompson stock screws and I was lucky enough to
run across some of the originals and am going to use them.
So, I have Enco catalog out tonight ordering the taps.
I am already wanting to change it to 7.62x25 and use the PPSH drum--I just really like plinking with the Romanian surplus. going to make one in that caliber.
I am definately
I'll get some pictures up soon. This is really a pretty simple build and I am thinking of doing it again and taking more pictures of how to create the trunnion / upper receiver so that others can recreate it.
Posted By: tommerr Date Posted: April 17 2008 at 9:25pm Please do post more in depth. I am curious as to how you drilled the bolt hole. Deep holes can be troublesome. Did you switch to a flat bottomed drill? ------------Tommerr
Posted By: gundoctor Date Posted: April 17 2008 at 9:43pm OK Tommer, I will explain without pictures since I can't get in the shop tonight. I didn't have to drill a deep hole. I created the trunnion and forward part of the upper out of an original demilled receiver. I cleaned up the sl*g and measured it--and it was 17 mm in the back and 20 mm in the front. I ordered drills this this size from Enco. I then turned a hollow mandrel to fit the front 2 demil pieces and welded them to the mandrel on each end, using a magazine to space the gap. I then removed the tube portion and front/rear fillers. Then I rewelded the "trunnion",including welding it to the mandrel in the "gaps". I did it this way instead of using copper so it would not be potential contraband (probably wouldn't be but why have to explain). I then squared the rewelded "trunnion" so that it would slip inside the square tubing. Then drilled out the hollow mandrel I had used to align the receiver using the two metric drills. Slipped it inside the square tubing and welded it up. I will get a tutorial on rewelding a receiver up so that others may see it--it is simple to incorporate a blocking bar in the reweld to prevent its use with an unmodified FA bolt. If doing a rifle build you simply do not drill out the forward part of the mandrel to original size-leave it smaller. This not only gives more strength, but will also keep an original (i.e. short) barrel from fitting. Then you simply turn down a legal 16"+ barrel to fit the new and smaller trunnion size.
You can see my http://www.weaponeer.net/forum/forum_posts.asp?TID=7054 &PN=1 - thread on rewelding a trunnion here .
Posted By: gundoctor Date Posted: April 27 2008 at 3:21am Installed my FCG. Since the lower receiver is wider than the AR in order to fit the Thompson Rear Grip, I made longer trigger and hammer pins. I also needed to make a longer safety. After thinking about it, I decided to use a HK type arrangement / retainer--and I had a broken cetme safety that I disassembled to get the lever and spring from. I will make the safety from a piece of 3/8" tool steel, a short piece of 1/8 tool steel, and the parts from the CETME safety. This is a pretty simple job.
Here is the FCG and new safety installed. My 14x24 tap came in so I also got the rear grip attached. I measured the angle for the grip bolt at 55*, and used a transfer punch to insure I got the hole in the right place. I also fitted the bolt head to the bolt body, and retained it with a single tool steel pin which also serves as a firing pin retainer. This will allow bolt disassembly if needed. Tommerr is right, drilling a hole through the hole in the hard bolt head for the firing pin retainer is a pain. I used a carbide endmill, and it fractured when I was nearly finished--I have no idea why--maybe something shifted. It was brand new . I really like the lower. Next, I need to get the lower attached to the upper and come up with a good magazine catch design. G3 pins (small ones) are the right length to attach the lower, but I am thinking of a "no lose parts" takedown design. The safety won't rotate upward to the position needed to remove it unless the lower is swung down away from the upper (like the HK / CETME). It is in the safe position below--it won't rotate upward to remove when attached to the receiver--and you can see the small, temporary detent for the fire position. If feels very "ergonomic".
Posted By: gundoctor Date Posted: April 27 2008 at 6:57pm Got a few hours in the shop this afternoon, and decided I wanted to feel the heft of the Suomi-Thompson when it was all put together. I had to mount a piece of 3/4"w x 3/8"thick steel to the rear of the receiver for the stock mount, and decided to also create a "slide on" t-slot to retain the rear of the lower. Here is what the completed rear stock mount looks like.
The "t-slot" (cut with woodruff key cutter) in the lower engaging the rear stock mount.
making the boss for the rear stock mount.
The M1 butt stock has a "hole" for a 0.600 round boss about 1/2" tall at the front screw. I turned a piece to fit this and then threaded it 1/2 x 20 to screw into the rear stock mount (3/8 x 3/4) which I had welded to the receiver. I then threaded this 14x24 for the short stock screw and using a transfer punch, marked the rear / long stock screw and drilled and tapped it 14x24. I made a forend iron to fit in the slot I left in the trunnion. I simply made this out of a piece of 1/2 sq stock and tapped it for the forend screw. I shaped it to make everything fit like I wanted, not to any particular blueprint or design. I haven't attached it yet to the receiver but I will probably either pin it or screw it.
I also worked on the mag catch. Since the new lower is deeper than the suomi, the mag catch is too short. However, when I looked at it I had an idea--why not use it anyway and then make something else to actuate it--probably through the forward part of the triggerguard ala Thompson. Here is the original Suomi mag catch in the recess I milled in the lower. I have not made the other part (to actuate it) yet., but it may be a simple "button" that protrudes into the trigger guard or I may make a lever like the Thompson.
Here is what it looks like all together. Holding this combination of two of the finest smg's ever made--the Thompson and the Suomi, and knowing the Thompson wood was likely on Iwo Jima and the Suomi probably killed Communists by the droves makes me feel pretty good about rescuing some of that history. The suomi drum is the perfect size for the horizontal forend--i.e., unlike the Thompson drums it is not uncomfortable using the horizontal forend. To be honest, it feels good. Yet to do: Forward takedown pin ( in lower). Sights. Shorten rear of receiver about 1/2" / shape and make an "end cap" that includes a recoil spring guide rod, pin barrel in, pin forend iron in. Finish mag catch., redo welds in trunnion. SHOOT IT! Polish and finish.
Here is why we do this: Some people simply don't respect these fine machines. They destroy them, make them illegal / hard to own, and look down their noses at those that appreciate them. My hybrid is not really a replica of anything, but it is a tribute to those fine arms makers who have had their creations intentionally destroyed in the name of "progress".
Posted By: USMCsean8531 Date Posted: April 27 2008 at 11:01pm I keep reading with envy! Great job and I love your ingenuity! ------------Semper Fi, Sean "If people don't kill people, but guns do kill people; Does that mean I can blame my pen for the mistakes that I make when Im writing?"
Posted By: Inabadhood Date Posted: April 28 2008 at 10:58am Looking Good!!!
Posted By: dcorb Date Posted: April 28 2008 at 11:43am I am interested in building one of these and some flavor of the SGN9, in fact I just ordered three more Soumi kits to share shelf space with with my other three Soumi kits. -------------
Posted By: dvanncvann Date Posted: May 02 2008 at 7:38pm Im working on something very similsr.
Posted By: dvanncvann Date Posted: May 02 2008 at 7:41pm
Mine uses a pps43 bolt, a soumi barrel and a 2xtm magwell. It will take drums or stick mags.
I really like the way you have done the trigger group and I have redesigned mine to more closely resemble the original. Great stuff!
Posted By: dvanncvann Date Posted: May 02 2008 at 7:42pm Receiver consists of a round receiver to house the PPS43 bolt that is inserted into square tubing.
Posted By: gundoctor Date Posted: May 02 2008 at 9:45pm Nice build! I considered using the roundtube with square tube build myself. The 1928 stocks are much more available than the M1 buttstocks. My free hint for the day is that Enfield buttplates will fit the 1928 Thompson buttstock with only a little bit of tweaking--and they can be had for about $5 and sometimes cheaper at gunshows.
Posted By: dvanncvann Date Posted: May 07 2008 at 7:13am test fired Monday.
Im waiting on the AR site parts to get a rear sight fabricated. Gundoctor, thanks for the FCG idea. Didnt mean to steal your idea but I couldnt help it.
Posted By: dvanncvann Date Posted: May 08 2008 at 7:46pm here she is ready for final sight in, duracoat and maybe a violin case.
Posted By: gundoctor Date Posted: May 08 2008 at 7:59pm It looks great!!! Did you use the original front site and "ring" from the suomi? I considered that and I think it looks great on your barrel / compensator if that is what you used? You should do your complete build in a thread and maybe enter this in the homebuilt challenge if you started it no later than April 1. The forum would be interested in more details on your fabrications for stock mounts, your bolt work, etc.
Posted By: dvanncvann Date Posted: May 09 2008 at 3:10pm gundoctor wrote: It looks great!!! Did you use the original front site and "ring" from the suomi? I considered that and I think it looks great on your barrel / compensator if that is what you used? You should do your complete build in a thread and maybe enter this in the homebuilt challenge if you started it no later than April 1. The forum would be interested in more details on your fabrications for stock mounts, your bolt work, etc. The front site is a soumi. I just raised the blade and reduced the ring size slightly. I started this one about the middle of April. I have a build thread posted over on Gunco. http://www.gunco.net/forums/f245/9mm-thompson-clon e-38091/ - http://www.gunco.net/forums/f245/9mmthompson-clone-38091/
Posted By: dvanncvann Date Posted: May 10 2008 at 8:15am And finally here she is all purdied up with WWII od green duracoat.
Posted By: dcorb Date Posted: May 10 2008 at 8:28am
Fantastic! You just convinced me I have to build one of these! Not like I really need another project.
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Posted By: weaponeer Date Posted: May 10 2008 at 2:27pm very nice work!!!!!!! ------------Weaponeer.net survives on donations made each Month by the membership. if we don't get enough donations, our hosting provider turns off the website, and only turns it back on after the hosting fee's have been paid. Please... every donation counts
Posted By: dcorb Date Posted: May 10 2008 at 4:20pm Well I am tossed up whether to use a Soumi bot or a PSH43 bolt for mine. At this point I am really only interested in a metal shopping list as I need metal for my other projects. I plan to order some square tubing but the two designs used two different sizes: 1 1/4" x .120 and 1 1/2" x .120, guess I will just order both. One design needs a round tube to fit in the square tube, not sure on the size. Need to figure out what soon as I need steel for my MAC builds, bending jigs, and I have an idea for the widget build caterogy.
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Posted By: dvanncvann Date Posted: May 11 2008 at 4:14pm dcorb wrote: Well I am tossed up whether to use a Soumi bot or a PSH43 bolt for mine. At this point I am really only interested in a metal shopping list as I need metal for my other projects. I plan to order some square tubing but the two designs used two different sizes: 1 1/4" x .120 and 1 1/2" x .120, guess I will just order both. One design needs a round tube to fit in the square tube, not sure on the size. Need to figure out what soon as I need steel for my MAC builds, bending jigs, and I have an idea for the widget build caterogy. I used 1 1/4 od x .058 wall round tube.
Posted By: tommerr Date Posted: May 11 2008 at 5:10pm I bought a half dozen Ppsh43 bolts for experiments. They are VERY SOFT and easy to machine. They are too soft to get a Rc reading. Yes, I have already destroyed one. It seems like I must destroy a few of everything. I see some challenges in converting them. They are not round so lathe drilling, for the firing pin, is not possible. If the hole drifts, the bolt is scrap. That is a very long hole. The Suomi is round. I now recommend that they be annealed to drop the hardness a bit. A good hardness range would be between 35 and 45Rc. 45Rc is normally seen as the edge of machinibility. Another good choice would be pre-hardened 4140. The hardness is approximately 30Rc. Machinibility is excellent and you do not have any heat treating problems. The down side is the milling necessary so the bolt will ride through the magazine to push a cartridge into the chamber. If you use a Suomi bolt, heat it at 950F for two hours. If you can file it, you are there. I do not recommend going over 950F. The hardness should be checked for safety reasons. ------------Tommerr
Posted By: jacattak Date Posted: May 23 2008 at 8:58pm
This is absolutely FANTASTIC !!!! Gundoctor, PLEASE PLEASE PLEASE post more pics and info on that front trunnion using the suomi magwell . Also I agree with an earlier poster, could you put all this on a cd for novices like me ? Heck I'll send a spindle of discs if you'd like !! By the way, new member and this is my first post here, thanks to everyone for all the great info. Back to topic, after seeing this thread I bought a couple Suomi kits and am gathering up some of the mentioned metals and parts to try and make one of these myself. It may be a little while before I get to start it, so I will probably have a ton of questions later. Enough babbling for now. Jacattak
Posted By: gundoctor Date Posted: May 24 2008 at 11:43pm I need to update on some things I've done and fill in a few more details but like every one else between work and family time to take pictures and post has been at a premium. I've completed a pretty neat rear site using M1 carbine parts and completed the endcap. I think everyone will like my solutions there. Maybe this build does warrant a really good step by step with more information, measurements, etc-- and I'll start thinking about putting that together. It will be better the second time thru because the first one is always a prototype that you know several places to improve before you're even done with it. I think it would be a good build to post in the special contributors section, and since you can join cheaper than most CD's sell for that should encourage some people to become site contributors. Additionally, I have already determined that I can make it convertible from 9mm to 7.62x25 in version 2. This is really neat because the 7.62 surplus ammo is one of the few ammo bargains out there right now.
Posted By: dcorb Date Posted: May 25 2008 at 9:07am I am looking foward to it as I want to build one.
Posted By: jacattak Date Posted: May 26 2008 at 8:48pm
A HUGE second to dcorb's post, Im already buying parts and supplies to get started whatever it takes to get ALL the info you have to offer on this project.
. Just tell me what I have to do to be a contributor or
Keep us posted. Jacattak ps. Do you have any suggestions for repairing a broken extractor on the suomi magwell section ? I was welding the front section back together and I didn't realize it was PINNED ON ! Any help would be GREATLY APPRECIATED !
Posted By: gundoctor Date Posted: May 26 2008 at 9:58pm I have been unable to find any new ejectors, but it would not be that hard to make them (if time is not an issue ejector out of about 1/2 of my kits
) I am able to salvage the
Additionally, I am considering making my own ejectors in the style of the Thompson. This is a simple design that simply screws in--would be easy to make and then heat treat and I believe would work great with the Suomi bolt in the square tube Suomi-Thompson build. ------------Fraternitas in Armum ™
Posted By: weaponeer Date Posted: May 26 2008 at 11:36pm looking forward to the full build details ------------Weaponeer.net survives on donations made each Month by the membership. if we don't get enough donations, our hosting provider turns off the website, and only turns it back on after the hosting fee's have been paid. Please... every donation counts
Posted By: jacattak Date Posted: May 27 2008 at 6:00pm Gundoctor, Time is NOT a problem, I have a cousin who works as a machinist and am thinking of showing it to him to see if he could make a couple for me. I am about to order 2 more Suomi kits to be sure I have all the parts I need (I expect to screw a few things up, like that
broken ejector!!) I must make an apology to all, I have neglected to say, "new guy here, and I have learned SO MUCH" just snooping the posts before I joined, you guys have an absolute GALAXY of info, especially for a novice like me. Thank you all. Looking forward to learning ALL I CAN !! Jacattak
Posted By: jacattak Date Posted: May 28 2008 at 9:41pm I have some bad news boys and girls, the M-31 Suomi kits seem to be drying up FAST !! Cope's has taken them off thier site (sold out ?) tnguns.com has lots of parts listed but when I tried to order from them I got a security alert warning that thier security certificate was expired or not valid (made me TOO nervous to order from them), As of 30 seconds ago militarygunsupply.com had 5 parts kits left, and while they come with a drum mag they are still $100, and finally I found akparts.com has some parts and kits ($80 with 1 stick mag) they seem a little pricey. So unless someone is hoarding the kits, or (hopefully not) the vendors are holding back watching the build threads and are going to bring out "a few we found in the warehouse" later at inflated prices (look at what is happening with the AK kits right now !!)we may be in trouble. I ordered 2 more kits from Cope's last night, hopefully I got the order in in time, so.....If anybody knows of any other vendors who currently have kits please let us know. later, jacattak
Posted By: tommerr Date Posted: May 28 2008 at 11:13pm Akparts does have kits at $80. $80 was expensive yesterday. Tomorrow that may be cheap. I hate to see whole kits purchased just to get the bolts. The Suomi's are too nice to waste just for the bolt. ------------Tommerr
Posted By: tommerr Date Posted: May 28 2008 at 11:28pm This might get me into quicksand but here is the germ of an idea. If you are buying a Suomi kit just for the bolt, perhaps we can do a bit of horse trading. The parts that you don't need traded to me for some work. 1. I would temper your bolt to 35 to 40Rc to make the machining easier. It will have good toughness and wear resistance. Rc hardness will be performed and reported. 2. The fixed firing pin will be removed. I made special punches to punch them out. 3. I will open the firing pin hole leaving the step for a foreward bushing. 4. I will turn down the bolt diameter. Your thoughts please. ------------Tommerr
Posted By: jacattak Date Posted: May 29 2008 at 12:41am Tommerr, actually I'm useing the bolts,barrel shrouds,magwells,and a couple other parts for various projects (well I hope to do various projects, I'm new to "scratch" building, but I have friends with machines and friends who are gunsmiths) but your proposition is something to consider. My biggest problem is, whenever I think "that's it, that's all the projects I'm going to start" one of you guys shows me a picture of some totally cool new design and it starts all over again. At least this time I got the parts kits BEFORE they all went price crazy and dried up !! (I found the AK bug WAY TOO LATE ! In the last 5 months alone Romy kits went from $99 affordable to $250+ and going,going,GONE !) later Jacattak
Posted By: Ironsite Date Posted: May 29 2008 at 11:56am Just called Cope's. They ran out of Suomi kits yesterday. He said it was his understanding that there were no more coming
Posted By: tommerr Date Posted: May 29 2008 at 8:41pm For a long time, the Suomi's sat and gathered dust. No one knew what to do with them. Promises were made but they were never realized. At one point, Centerfire was reducing the price to 1/2 if you bought any other kit. I bought a kit and I was astounded at the quality. It equals or betters the Germans best quality. I made the Suomi the center of my building efforts. I thought that the supply would never end. The fact that the long neglected Suomi kits are drying up is a sign of the times. All kits are drying up. The vanishing and obscure Suomi proves that to me. As a Suomi purist, or close as one can get considering the laws, I am saddened that parts are being used for other things. Oh well, I was saddened when they stopped using flint on arrows and instead put it into lighters. I still have three tons of flint for arrows. I also have suomi kits for my future. ------------Tommerr
Posted By: gundoctor Date Posted: May 29 2008 at 9:59pm
You have to buy kits and parts when they are available and people haven't figure them out yet. I buy kits for kits, kits for their parts, and individual parts to make kits. Any of this stuff will only stay cheap and available until (1) enough demand is created for it and/or (2) the supply dries up (3) the rest of the parts (receivers, compliance parts, barrels, etc) to finish "partial kits" are readily available. Welcome to 1+2+3 for every "parts kit" that I know of. I will wager that buying 200 of anything would be nearly impossible today--while a year ago you could buy this quantity of just about any kit out there. The one stepchild appears to be the PPSH43, which can be bought sans barrel for less than the mags are worth. That will last only until someone figures out something neat to do with it.
------------Fraternitas in Armum ™
Posted By: Ironsite Date Posted: May 30 2008 at 11:16am I'm chalking this up as a lesson learned. I'm glad I got at least one Suomi. I'm going to start buying what I can when I can.
Posted By: gundoctor Date Posted: May 30 2008 at 3:08pm There is another lesson in the current situation. We don't need "kits" for this hobby to be a lot of fun. Except for the barrels, every part can be made with a file and hacksaw if needed. And many parts are readily available and cheap--such as FCG's, stocks, grips, extractors......... Putting what is available with what you can make at home is a lot of fun, and I believe that people will step up and make some "missing parts" for others who lack the tools to do so. We have plenty of builds on this forum where there is more machine work (time and $) in converting a part (i.e. a FA bolt to a semi bolt) than it would take to make a brand new part. This is where our hobby is going and this forum is where it is going to happen. I admit that part of this hobby is recreating a past weapon in a legal, semi auto version--but you can do that from scratch as well.
Posted By: dcorb Date Posted: May 30 2008 at 4:16pm I am giving the build from scratch approach in my tube guns and having a fun time doing it. I am no way a machinist but it is fun learning the basic metal work skills. The really cool thing sharing my experiences which include the mistakes is the feedback I get. Other people provide solutions and new ideas. Many new ideas are spawned from documenting the build process.
Posted By: dcorb Date Posted: July 04 2008 at 1:19pm When I get around to building to building my Soumi Thompson it might look something like this:
http://www.tactical-life.com/online/products/thomsp 1;ns-ta5-pistol/?right=related - http://www.tactical-life.com/online/products/thomspons-ta5-p istol/?right=related
Posted By: garden_t00l Date Posted: August 14 2008 at 9:55am I like what you have done. When I first saw the soumi kits the first thing I thought was that could make a tommy knockoff. Wheres a good place to buy Thompson furniture at fairly cheap?
Posted By: jacattak Date Posted: August 19 2008 at 11:28pm Step 1 done, re-welded one of my Suomi Trunnion/magwells. Not too bad for a novice welder with a Harbour Freight "Splat-o-Matic". Now to get some more cash and parts and help and more help and........
------------if you can't laugh at your OWN mistakes, life isn't worth living
Posted By: blurrededge Date Posted: February 23 2011 at 2:47pm Gundoc. On Page 2 of this thread you posted: Tomerr, the chemistry would help on the bolts to allow more flexibility in working with them if they can be safely annealled and rehardened. Testing steels for chemistry is out of my purview.
I did not anneal the bolt for the suomi thompson. I cut it with a cut off saw (abrasive) with a wet rag around the bolt head. I then used the lathe to face the rear of the cut off bolt head. This is the same way that I cut and reweld mauser bolts and receivers to shorten them without changing the heat treatment in the critical areas (receiver ring and locking lugs of bolt). I do not intend to weld on the bolt head, but planned to use some short pins that are inserted through the bolt body into it--these pins will then be welded over (but the welding will be pin / bolt body, not to the bolt head. This will "capture" the bolt head in the bolt body. In this way I hope to maintain the intergrity of the suomi bolt head and its heat treatment. These pins will not take the force of recoil, as that will be borne by the shoulder in the bolt body. As an alternative, I am considering leaving the bolt two piece and using a single cross pin to both retain the bolt head to bolt body and the firing pin. I've welded on the receiver pieces a good bit, and my guess is that these are mild steel in that they weld very good with none of the spitting and brittleness usually associated with higher carbon steels. The underlined quote above interrests me greatly... can you provide any elaboration, or even photo's? I have thought about this many times... but was never quite sure it could be done ------------Semper Fi
Posted By: gundoctor Date Posted: February 26 2011 at 5:55pm Nothing complicated. Keep the area's you don't want annealed cool while welding. Weld with your choice of methods. Then spot anneal the welds if you wish. You can use commerical heat paste or wet rags or even submerge the locking lugs in water while you weld the bolt vertically (not necessary)
Posted By: blurrededge Date Posted: February 28 2011 at 11:13am How did you account for the extractor length, and what about shortening the bolt? ------------Semper Fi
