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Patches and Stickers for sale here

File 151537899348.jpg - (1.81MB , 3591x852 , P1066153.jpg )
106706 No. 106706 ID: 19518e
There's a machine gun thread a while ago but I felt like I should start a specific thread for firearms fed by belts.

Mostly because of this MG34 that followed me home.

Since this really is the first rifle of this type that I've had to play with, I'm a little out of my element. This is a TNW semi-auto only 7.92x57 and I wouldn't mind learning everything I can about this particular piece.
Expand all images
>> No. 106708 ID: 19518e
File 151537913173.jpg - (1.46MB , 1920x1440 , P1066158.jpg )
This will be a bit of an ongoing project thing as I track down belts, belt tins, and a spare barrel so I don't mind people throwing in their own belt guns or whatever as I mosey on from the basement gun TLC table to the shooting range.
>> No. 106710 ID: 19518e
File 151537963639.jpg - (1.42MB , 1920x1414 , P1066161opsec.jpg )
This week or early next weekend I should be taking this apart for a closer examination and so on. I know a couple guys that have a lot of experience with these kinds of things so I'll be learning, and subsequently hoping to show some finer details of these belt-feds.

Of course, as previously stated, discuss and post at your leisure, everything will be appreciated.
>> No. 106711 ID: 1519ac
>> No. 106712 ID: 9dcda2
Doooooooood. That's fuckin' sweet.
>> No. 106713 ID: a70f4c
File 151550733515.jpg - (115.95KB , 911x737 , German WW2 MG-34 twin 50-rnd drum carrier 'Gu.jpg )
How you set for belt drums?
- German WW2 MG-34 twin 50-round drum carrier 'Gurttrommeltrager 34'.
>> No. 106714 ID: a70f4c
File 151550818750.jpg - (426.39KB , 1600x1600 , German WW2 MG-34 50-round drum Gurttrommel 34 1.jpg )
- German WW2 MG-34 50-round drum Gurttrommel 34.
>> No. 106715 ID: a70f4c
File 151550844570.jpg - (177.82KB , 1600x1410 , German WW2 MG-34 50-round drum Gurttrommel 1.jpg )
>> No. 106716 ID: 19518e
I found a belt and I'm still looking for gurttrommels. I think there's a place with a barrel around and my buddy picked up some ammo.

Sadly this weekend won't get too much done, got plans. Probably next weekend I'll be able to get some trigger time though, pretty hype.
>> No. 106717 ID: a70f4c
File 15155710269.jpg - (85.98KB , 1155x1155 , bullets, German 7_92x57mm 340 rds_ 8mm Mauser 150g.jpg )
How much does 8mm Mauser (7.92x57) cost nowadays?
The online deals seem to go for around $.80/round:
>> No. 106718 ID: a70f4c
File 151557110185.jpg - (2.37MB , 3648x2736 , bullets, German 7_92x57mm steel cased s_S_ ball am.jpg )
Four 7.92x57mm Mauser rounds and three World War 2 era 15-round ammunition boxes. Patr. sS (Patrone schweres Spitzgeschoß—"Cartridges, heavy, pointed-bullet") German ball ammunition with a heavy bullet. eej. 8 L. 41 (Lieferung 41, "Batch 1941") means it was produced in August, 1941. Für MG (Für Maschinengewehr) means The cartridge cases were made extra sturdy for machine gun use. Patrh. S. (Patronenhülsen Stahl) means that the cartridges have a steel cartridge case.
>> No. 106719 ID: a70f4c
File 151557345436.jpg - (614.76KB , 1656x1242 , bullets, German 7_92x57mm 8mm Mauser w stripper cl.jpg )
>> No. 106720 ID: a70f4c
File 151557355392.jpg - (371.29KB , 2048x1235 , German WW2 MG-34 7_92x57 LMG 6.jpg )
>> No. 106721 ID: a70f4c
File 151557359358.jpg - (168.27KB , 1164x1350 , German WW2 MG-34 on a Sd_Kfz_ 250 halftrack 1.jpg )
>> No. 106722 ID: a70f4c
File 151557361435.jpg - (84.80KB , 2048x1361 , German WW2 MG-34 7_92x57 LMG 7.jpg )
>> No. 106723 ID: a70f4c
File 151557364750.jpg - (787.90KB , 3500x2649 , German WW2 MG-34 Waffen-SS soldiers from 'Wik.jpg )
>> No. 106724 ID: a70f4c
File 151557368692.jpg - (573.30KB , 1600x1337 , German WW2 MG-34 7_92x57 LMG 8.jpg )
>> No. 106725 ID: a70f4c
File 151557384418.jpg - (861.37KB , 5184x3456 , Yugoslavian M76 7_92x57mm semi-auto DMR by Zastava.jpg )
Another interesting 8mm Mauser semi-auto is the Yugoslavian M76 7.92x57mm DMR by Zastava.
>> No. 106726 ID: a70f4c
File 151557408286.jpg - (885.85KB , 5184x3456 , Yugoslavian M76 7_92x57mm semi-auto DMR by Zastava.jpg )
No belts, but 5-round box mags and the sell for around $1200 to $2000.
>> No. 106727 ID: a70f4c
File 151557415347.jpg - (287.39KB , 1600x1066 , Yugoslavian M76 7_92x57mm semi-auto DMR by AWO Zas.jpg )
M76 Yugoslavian Sniper 8mm Mauser by AWO - Zastava
>> No. 106728 ID: a70f4c
File 151557417386.jpg - (311.96KB , 1280x853 , Yugoslavian M76 7_92x57mm semi-auto DMR by AWO Zas.jpg )
>> No. 106729 ID: a70f4c
File 151557422394.jpg - (274.11KB , 1280x853 , Yugoslavian M76 7_92x57mm semi-auto DMR by AWO Zas.jpg )
>> No. 106730 ID: a70f4c
File 151557424675.jpg - (210.87KB , 1280x853 , Yugoslavian M76 7_92x57mm semi-auto DMR by AWO Zas.jpg )
>> No. 106731 ID: a70f4c
File 151557448445.jpg - (315.09KB , 1600x1066 , Yugoslavian M76 7_92x57mm semi-auto DMR by AWO Zas.jpg )
>> No. 106732 ID: a70f4c
File 151557498157.jpg - (659.56KB , 3500x2446 , German WW2 MG-34 7_92x57 LMG 9.jpg )
Back to MG-34 stuff.
>> No. 106733 ID: a70f4c
File 151558160414.jpg - (582.75KB , 2272x1404 , German WW2 MG-34 on a Lafette tripod 1.jpg )
So... you going to go full Lafette tripod?
>> No. 106734 ID: 19518e
My current source for ammo ends up being about $1.1 per round in snow communist dong. Honestly it's quite reasonable for a less standard caliber that will keep the gun happy and isn't going to be corrosive old piss.

At this point I'm planning to keep it a bit more simple and sling it. The MG34 is quite practical and portable so this is definitely coming with me to my quiet little shooting spot innawoods so I can bully a gong for like ten minutes straight.

Personally, I feel that I would rather have an M2 than an MG34 with the fancy tripod business; not that I wouldn't want a Lafette tripod or anything, it's more that I don't want to detract from what made me choose the more portable of the available belt-fed non-restricted firearms up here.
>> No. 106735 ID: a70f4c
File 151558537616.jpg - (328.91KB , 2560x1706 , German WW2 MG-34 7_92x57 LMG 11.jpg )
Bring some friends to play in the snow.
>> No. 106736 ID: a70f4c
File 151558545591.jpg - (275.42KB , 3000x1993 , German WW2 MG-34 machine guns captured in the Batt.jpg )
It's amazing the things you may find in the snow.
German WW2 MG-34 machine guns captured in the Battle of Moscow.
>> No. 106737 ID: a70f4c
File 151558551758.jpg - (352.09KB , 1811x1258 , German WW2 MG-34 17-gun AA mount 1.jpg )
Round up 17 MG-34s and build something like this.
>> No. 106738 ID: a70f4c
File 15155856249.jpg - (354.58KB , 1280x1743 , German WW2 MG-34 with a telescopic sight 1.jpg )
But finding an MG-34 telescopic sight might be more difficult.
>> No. 106739 ID: a70f4c
File 151558576839.jpg - (720.30KB , 2000x1333 , German WW2 MG-34 on a motorcycle 1.jpg )
You can use your MG-34 as a snazzy motorcycle accessory.
>> No. 106740 ID: a70f4c
File 151558583611.jpg - (738.89KB , 2048x1179 , German WW2 MG-34 7_92x57 LMG 10.jpg )
>> No. 106756 ID: 19518e
Thanks Bats.

Sadly some stuff has gotten in the way of range time this weekend. I plan on bringing friends next time I can be out there though, the more the merrier.
>> No. 106758 ID: e0deaf
File 151578642377.jpg - (645.51KB , 1920x919 , MG42_3945.jpg )
>Mostly because of this MG34 that followed me home.


I've always found the MG34 to be hugely underappreciated compared to the MG42 due to media exposure etc. The MG34 is of a lot higher quality than the MG42.

I know someone that owns both, and by far the MG34 is his favorite too, because it can be shot a lot more accurately, both in semi & full auto.
>> No. 106759 ID: 19518e
I've shot a semi-only MG42 and I did end up looking for an MG34 because of the latter's construction, as you said. I do like the MG42's aesthetics more, to be honest.

I mean it's just such a pretty gun. The MG34 is a little simple and awkward-looking but I still like it even if the 42 is the sexy one, a bit like a waifu that might not be a smoking hottie but will stand by you forever.

Hopefully it'll be somewhat OK. Barrels for these things are a little "well broken-in", maybe I'll find one with good rifling eventually.
>> No. 106764 ID: a70f4c
File 15158032783.jpg - (908.00KB , 2048x1290 , German WW2 MG-42 7_92x57mm GPMG on a Lafette tripo.jpg )
I have read accounts of the inaccurate "cone of fire" that spews out of the MG-42. Such as a G.I. who was ambushed by an MG-42 and he froze in terror while that machine-gun sprayed him with 1,200 rounds/minute, like being showered with sparks from a gigantic Roman candle. His buddies killed the German MG crew and the one US trooper who was the sole target of all that machine-gun fire noticed that he was untouched, but that the area around him was peppered with bullet holes. "Hitler's Zipper" could surely pound out the lead (the M1919 Browning MG only fired 400 to 600 rounds/min), but not as accurately as the MG-34.
>> No. 106769 ID: e0deaf
File 151583673453.jpg - (141.59KB , 1600x1076 , MG-1453568737797.jpg )

The MG42 was more regarded as an area denial type thing, which would hit by sheer volume at extended range, rather than by accurate fire.

Now, the truth is probably somewhere in between. The specific quote you have may have been from an already shot out barrel for instance due to the machine gunner not having properly maintained his gun and not having swapped barrels frequently enough.

>Barrels for these things are a little "well broken-in", maybe I'll find one with good rifling eventually.

Shouldn't be too hard to source new-ish barrels. Of course, the problem there is cost. Their respective owners know what they have, obviously.

Do you mind sharing ballpark pricing on what you paid for this beauty?
>> No. 106771 ID: 19518e
I paid a little under the current market price for these. Up here they retail 6.6k (7500 total after tax/shipping) from most places. My price was good as it included a few accessories that are coming soon, and some special TLC from a respected belt-fed gunsmith of sorts. I'll also be getting a crash course from him on these things.

I've heard from various sources that TNW need some work to function like a sewing machine; without this hand-fitting and tuning, they run a little rough and can be prone to stoppages. From cycling the action manually, I can definitely see that there is truth to these rumors.
>> No. 106774 ID: e0deaf
File 151587463481.jpg - (94.18KB , 701x657 , MG34-1486730868358.jpg )

Sounds good.
>> No. 106775 ID: e0deaf
File 151587559248.jpg - (178.69KB , 600x419 , 1266954301202.jpg )
Did you know that all Nazi tanks used MG34 for hull guns?

It's because MG42 barrels pop out to the side, whereas MG34 swivels/rotates to remove the barrel.
>> No. 106777 ID: 19518e
Forgotten Weapons has a good MG34 video and I remember they mentioned that even with the adoption of the 42, lots places and armored vehicles still used the MG34 for that reason.

I'm still a little salty that I wouldn't be able to go full Jin Roh despite the advantages of the MG34 over its successor.
>> No. 106781 ID: a70f4c
Yeah, the way the MG-34 and 42 can quickly remove their barrels were great advantages to other machine-guns like the Browning M1919, although certain light machine-guns like the Bren Gun had mechanisms for quickly swapping out their barrels.

Gunsmithing Disassembly Browning 1919 Machine Gun Disassembly and Reassembly (Gunworks) https://youtu.be/AP1T7ZRzW1s
>> No. 106782 ID: a70f4c
  Browning 1919A4 vs. German MG-34 Part 1 https://youtu.be/8VDxAv3--RY
>> No. 106783 ID: a70f4c
  Browning 1919A4 vs. German MG-34 Part 2 https://youtu.be/qh-BlCTK3lo
>> No. 106784 ID: a70f4c
  MG-34: The Universal Machine Gun Concept https://youtu.be/E-KgQ-OZJZ8
The MG34 was the first German implementation of the universal machine gun concept - and really the first such fielded by any army. The idea was to have a single weapon which could be used as a light machine gun, heavy machine gun, vehicle gun, fortification gun, and antiaircraft gun. The MG34 was designed to be light enough for use as an LMG, to have a high enough rate of fire to serve as an antiaircraft gun, to be compact and flexible enough for use in vehicles and fortifications, and to be mounted on a complex and advanced tripod for use as a heavy machine gun. Mechanically, the MG34 is a recoil operated gun using a rotating bolt for locking. It is chambered for 8mm Mauser, and feeds from 50-round belt segments with a clever and unique quick-change barrel mechanism. The early versions were fitted with adjustable rate reducers in the grips allowing firing from 400 to 900 rounds per minute, and also had an option for a top cover which would fit a 75-round double drum magazine. Both of these features were rather quickly discarded, however,r in the interest of more efficient production. However, the gun fulfilled its universal role remarkably well. The MG34 was considered a state secret when first developed, and despite entering production in 1936 it would not be formally adopted until 1939 - by which time 50,000 or so had already been manufactured. It would comprise about 47% of the machine guns in German service when the Wehrmacht invaded Poland, but would be fully standardized by March of 1941. It was replaced by the MG42 later in the war, as that weapon was both faster and cheaper to produce and also required substantially less of the high-grade steel alloys that Germany had limited supplies of. However, it would continue to be produced through the war, particularly for vehicle mounts.
>> No. 106786 ID: f2172d

Funnily enough, my dealer picked up a MG34 parts kit this week. The barrel is in surprisingly good shape, waffenamt and everything. He's debating whether to get a semi-receiver from TNW and build, or just flip the kit alone.
>> No. 106836 ID: 0adccc
File 151642619979.jpg - (2.17MB , 3264x2448 , DSCF5068.jpg )
Heeey I have one of these!

I had issues with the original sear on the bolt carrier wearing down after ~250 rounds from the manu. Advise to inspect, check for potential slipping while the bolt is camming. Replacement seems fine so far, but I don't have too many rounds through it.

Also, the milling was very rough on my charging handle slot, and the handle would get stuck on it until I filed it down a little, then everything runs great. Also had some feeding issues for the first couple hundred rounds, then it works fine. The rifle prefers a thicc grease, they recommend, and I love, TW25B.
>> No. 106839 ID: 19518e
I have a very knowledgeable friend coming to fit the gun up and later teach me the subtleties. He keeps belt feds and shit running as a job and has owned like half a dozen of various canuck-legal belt-feds so he knows what's up.

You input was actually basically what he told me in the short conversation we had on the subject, so your experience is quite typical. We are actually thinking about making replacement semi-auto sears from better steel as the standard ones seem to all be quite soft.
>> No. 106845 ID: 0adccc
Good to know. If you guys do, please post on /trade/ or gimme your email, I'd be interested in one. They replaced mine for free, but a higher quality one would always be appreciated.
>> No. 106846 ID: 19518e
Email in the field, send me one and I'll let you know when stuff might be happening.
>> No. 106981 ID: 7fecba
File 151814025188.jpg - (799.38KB , 2899x1446 , IMG_0733.jpg )
Why We Don’t Use Turkish 8mm Surplus https://www.forgottenweapons.com/why-we-dont-use-turkish-8mm-surplus/
There is a lot of Turkish surplus 8mm Mauser ammunition on the market here in the US. It used to be super cheap (under 5c/round), but in the last few years I have seen it selling for more like 30c/round. It’s usually the least expensive option for 8mm ammo, and it can be identified by its Turkish crescent in the headstamps, one-piece brass clips, and crude bandoliers (7 pockets with 2 clips in each). Whenever I am asked, I always urge people to not use it in self-loading rifles. It is safe enough in bolt actions, but that’s IT. One would be better advised to buy it only for the projectiles (or really, just don’t buy it at all).

Why? Because it’s overpressure and has bad primers (lots of hangfires), thanks to poor storage over the decades. I believe the powder granules have deteriorated and the surface area increased, leading to a much faster burn rate than when originally made, and thus excessive pressure.

Now, I have encountered plenty of people who claim to have fired thousands and thousands of rounds of Turk surplus without any problems. I have no doubt that they are telling the truth – but the very next round could well change that streak for them. I have one friend who is missing a couple fingers from an incident in which a round of Turk surplus he thought was a dud detonated while he was ramming it out with a cleaning rod – the rod took off his thumb and the bullet took two more fingers.

I am aware of at least half a dozen machine guns damaged or destroyed by it as well. Too many machine gun owners are penny wise and pound foolish, spending tens of thousands of dollars on historical machine guns and then firing the cheapest ammo they can possibly find (ie, Turkish surplus 8×57). This came to my mind recently when I noticed that a friend had a remnant from a repair job on a caliber-converted (because cheaper!) Browning 1919 that had its sideplates ballooned open by Turk 8mm. Here’s the top cover:
>> No. 106982 ID: 7fecba
File 151814030280.jpg - (606.11KB , 2717x1148 , IMG_0734.jpg )
Yeah, it’s supposed to be flat.

Please, guys, don’t use this ammo. If you absolutely must, then stick to bolt action Mausers, and understand how to handle hangfires safely. But don’t let this be your 1919 or MG34 or MG42 or FN49 or G43 or Hakim. Or your fingers.
>> No. 106983 ID: 7fecba
File 151814058611.jpg - (544.31KB , 2334x1364 , 6eae85f35145c1386576dd49e94b75292aa4bd78.jpg )
The 7.9 x 57mm cartridge cases are from Turkey as signified by the star & crescent in the headstamp surrounded by the letters " T C " which stand for “Turkiye Cumhuriyeti” or the Republic of Turkey.
The letters " FS " stand for the ammunition production facility in Turkey, the exact meaning remains uncertain but suggestions are Fisek Sirket or Fisek Sube i.e. Ammunition Company or Branch. And as expected the “1940” or “1947” in the headstamps tell the year of manufacture.
Information is from: Headstamp Guide: Ammunition with Turkish and Arabic Markings, Ken Elks, 2016. https://forum.cartridgecollectors.org/t/wwii-8mm-mauser-headstamp-help/23810/4
>> No. 106984 ID: f2172d
>This came to my mind recently when I noticed that a friend had a remnant from a repair job on a caliber-converted (because cheaper!) Browning 1919 that had its sideplates ballooned open by Turk 8mm

This explains what blew up my old dealer's 1919. He was using surplus Romanian 8mm and we had an out of battery detonation.
>> No. 106989 ID: 19518e
Life stuff has been getting in the way of range time/up dates and so on. Might be a few more weeks to a month or so before I can do a whole lot with the MG34.

Ain't none of that garbage getting anywhere close to my fräulein. Right now I'm starting off with a few boxes of PPU 198gr BT FMJ.
>> No. 106990 ID: 19518e
File 15183999558.jpg - (123.56KB , 839x896 , drum_drum.jpg )
I did manage to find a gurttrommel. I have some feelers off for the extra bits, hopefully updates won't be months away, but shit's a little weird so I can't make any promises.
>> No. 107016 ID: 19518e
File 151906943760.jpg - (1.23MB , 1920x1440 , dsfargeg.jpg )
So I did manage to get out there with the MG34, but she'll need some more TLC before it'll run smoothly.
>> No. 107017 ID: 19518e
File 151906958492.jpg - (486.25KB , 1434x1020 , dfdasfd.jpg )
So there were two little hiccups. One was the light firing pin spring, an easy enough fix...

Except I didn't have any stronger springs on hand.
>> No. 107018 ID: 19518e
File 151906968724.jpg - (513.76KB , 1587x861 , dsdasfadsf.jpg )
So the quick solution just to fire off a round or two was fairly straightforward.
>> No. 107019 ID: 19518e
File 151907018682.jpg - (905.22KB , 1920x1080 , gasdfsd.jpg )
Second hiccup was the ejector pin. It's a little too long, and when a case is present during the firing cycle, the pin wedges against the ejector plate and the bolt seizes up. We can see this issue quite clearly as normally the bolt should never stop where it is seen in this picture. We can even see the ejector pin against the underside of the ejector plate (that piece with the two small screws)

I'll have to work that in next time I'm out shooting because it's one of those things that you can't really tune on a bench. The rifle cycles fine when racking the bolt manually, but when the action is cycling under fire, the pin's relation to the plate becomes a point of higher "stress" as there's force acting on the pin.

Even if I only fired a handful of rounds in what pretty much amounted to single-shot "bolt action" shooting, the potential for awesome is very high once the gun is properly set up.
>> No. 107020 ID: 1519ac
I don't quite understand what's going on here. Does heat raise the sensitivity of primers or something?
>> No. 107021 ID: 0adccc
>light firing pin spring

Da fuk? What kind of spring constant do you have on that? Is it factory? When I got mine, the spring was RIDICULOUSLY strong. I've had to cut off a few coils just to make the trigger stop sucking. I'll try to compress the spring as I have it to maximum compression to see where we're at. I'd like to replace this spring with something designed for commercial primers instead of hard-as-fuck south american surplus (which was cheap when the TNW rifles first went into production), which would help clean up the trigger a lot more (and hopefully reduce the force on the aforementioned sear collar and lever).

And I'm sure you learned to wear gloves when operating it in bolt action mode. The knurling on the bolt handle is fairly aggressive.

I'd also recommend picking up a new production mainspring online or something if yours looks used, after I replaced mine, it felt like it ran a bit smoother, and it wasn't expensive. Further, if yours is old stock, you might want to get a replacement buttstock as well (I didn't though). NFA guys with them down in Portland told me to be careful since the stock is thin in places, and theyve had cracks/breaks...then again, who knows how well old fudds treated these things and could have dropped them on the stock or something. There's some polish kid on ebay who makes beech repros.

I also had some issues with the pawl slipping the belt, but that cleared up after 2-3 belts.

The gurttrommel required filing to fit mine, btw, and more spring cutting was involved (maximum compression was not open enough to get the clip over the guide) but mines a post-war yugo which had obviously not seen use.
>> No. 107022 ID: d44f9d
Yeah the stock spring was replaced with a lighter one as the stock ones are stupid. The gun worked on the bench with empty primed cases in regular room temperature, but once it was taken to the cold, no rounds could fire even when I tried cycling them back and hitting them again.

I have some slightly heavier 1911 springs on order. The trick is finding a spring light enough to make the trigger not terrible but heavy enough to fire reliably.

This was a 14lbs 1911 spring and just warming the rounds up a but was enough to let them fire so there's not a whole lot of spring force missing to make it reliable. A lighter firing pin also increases reliability in cycling normal ammo as it reduces the force required by the main spring to close the bolt.
>> No. 107023 ID: 7fecba
File 15191799095.jpg - (73.86KB , 742x554 , German WW2 trooper with a smile & some goggles.jpg )
I heard gunsmiths commenting that German weapons had notoriously stiff springs. I had a WW2 German Mauser K98 and a Walther P.38 and those had stiff springs. Firing pins really put deep dents in the primers.
>> No. 107796 ID: bbee29
File CIMG0946.webm - (154.03KB )
Welp it's been quite the learning experience, and I feel like I'm closer to understanding the fine details in operating and maintaining the semi-auto MG34.

When I was doing my first shots and trying to diagnose the issues with mine, I completely overlooked the booster. The MG34 is recoil operated, but it's assisted by a muzzle device that turns the barrel into a bit of a gas piston to give the system a bit more oomph, and also allow for adjustment between 85 grain aluminum core bullets and regular heavier grain bullet ammo like 198 grain FMJ. As it turns out, the booster in my gun was a "9mm" booster, made for the aforementioned aluminum core ammo. This drove the action much too hard as I was shooting PPU/Prvi Partizan 198 grain FMJ. The action speed was so high that the ejector wore out in ~20 rounds.

Here is a single shot I fired as a test to isolate problems because the belt and related mechanisms could induce malfunctions that would complicate diagnosis. We can clearly see the problems caused by over-boosting, parts wear aside. The brass in this shot slipped off the extractor as it was being struck by the ejector pin, thus failing to eject and getting fed back into the chamber.
>> No. 107797 ID: bbee29
File 153887551860.jpg - (743.81KB , 2120x1576 , bewst.jpg )
So I made new boosters. The way to "dial" down a booster is simply to bore a larger exit hole, allowing more gas to escape and less gas to push on the crown of the barrel.

They're simple enough, I made 4 in total, not all shown here, in various sizes from 10mm to 11mm. I don't exactly need that many, but I don't mind having a "spare" that I can bore out later if I need another size for whatever reason. The original is the one sporting patina in the middle.
>> No. 107798 ID: bbee29
File 153887578424.jpg - (58.62KB , 1600x1200 , IMG_3105.jpg )
I also made new ejector pins, they're dirt simple so not much use going into them. I made a couple out of mild steel bullshit so I could easily file them at the range if they needed some minor tweaking. Whereas the original hard steel ejector lasted but a handful of rounds, with the new larger exit hole booster installed, even the mild steel ejector lasted almost a hundred rounds.

I'll order some better steel (4mm hardened dowel pin) and make some good ejectors.
>> No. 107799 ID: bbee29
File underside_bolt.webm - (820.87KB , underside bolt.webm )
With the new booster in place, things started to go a little better. As we can see in this video, the bolt speed is much more reasonable, opening at about the same rate as it closes under spring tension.

I do believe the main recoil spring driving the gun is a little old. I'll have to order one of those as well, or make one, not sure yet.
>> No. 107800 ID: bbee29
File giv'er_pt1cropped.webm - (1.59MB , giv'er_pt1cropped.webm )
Needless to say that after this string of rounds, I now feel that this purchase was worth every penny. I agree with Ian McCollum with semi-auto belt-feds not being worth the trouble in the United States of America but here in no-fun land this is by far the best purchase I've made in ages.

>> No. 107802 ID: bbee29
File giv'er_pt2cropped.webm - (1.00MB , giv'er_pt2cropped.webm )
I've thought about getting a 1919 or an M2, but it would be quite a lot more difficult to do this (webm related) with other belt-feds that can be acquired up here. I might end up tracking down an MG42, just because it's that pretty.

At this point all I need are some more belts, a spare barrel or two, and tons of ammo.
>> No. 107902 ID: 1ee05f
nice finish. considered crawling your feed to make it even better?
>> No. 107903 ID: 4eaeff
File 154057259876.jpg - (150.60KB , 1200x265 , 34_308_CONV1__53231_1455823550.jpg )
Waiting on getting my 34 from TNW on a brand new build. Hopefully it works out of the box, but I've seen enough issues with other people's that probably won't be the case.

In my case I intend on immediately converting it to shoot .308 because 8mm ain't cheap anymore. Involved in the process is modifying the feed tray to accept a spacer for .308, a new barrel (slimmer profile for the recoil operation as .308 has less oomph than 8mm), a narrower booster cone, and a top cover feed pawl modification that is longer which puts pressure on the shorter .308 round (which can be used with 8mm too).

Will report back as to how the .308 conversion goes once I get it all set up.
>> No. 107905 ID: bbee29
File 154060032853.jpg - (735.55KB , 1557x1545 , mousel.jpg )
Wasn't concerned about surface finish, just dimensions. It's not really visible from anywhere once inside the muzzle assembly so making it pretty was not a priority. Picture related, if you're worried about the surface finish while looking at this I'm afraid the autism is in terminal phase. Luckily if you are looking at it like this, you won't have to wait long for the euthanasia.

>double stamped 4
I'm terrible at stamping shit ffffffffff

>8mm isn't cheap
I'm kinda torn. The 8mm is glorious and original, also from what I've heard, it'll be more reliable once my TNW is running well. But then there's the cheap .308 Win stuff. If it's reliable, shooting more would be fun, but I doubt it would run properly without a lot of work. I think that for now I'll stick to 8mm until all my current minor issues are sorted out despite the seductive cheapness of 308.

I know a guy with a legitimate full giggle MG34 (he's allowed to have it, horsecops please go and stay go), and he said we could compare MGs and I could measure/take notes on the original parts.
>> No. 107907 ID: faf462
It's fucking cool that you got an MG34. I dig the slomo.

Buuuutt... just can't do semi-auto conversions of machine guns. Like a semi auto KRISS Vector, PS90, 1919, or Suomi. All would be amazing in full auto, but pretty pointless in semi.

I did shoot a semi auto MG42 some guy built out of a parts kit. I was amazed at how much it recoiled.
>> No. 107908 ID: bbee29
I agree with you. If it wasn't for my unfortunate location, I don't think I'd have a belt-fed either, unless I was able to scrape up enough pennies for a full auto one.

That said, I disagree with your thoughts on the Kriss Vector. That gun is retarded in any configuration, and is by design a failed abortion that only has a completely flawed concept to begin with and space-pew-pew aesthetics to ride on. I can forever hear the tortured screaming of it's machine spirit, begging "kill me, it hurts to live".
>> No. 108420 ID: e6ec85
File 15553543211.jpg - (1.35MB , 4032x3024 , signal-attachment-2019-04-14-223529.jpg )
Well, I managed to finally take my 34 out to the range the other day and shot it in .308. It fed and chambered properly after installing the necessary parts for the conversion (feed tray block, barrel, and extended outer pawl to push the shorter round down).

Had an issue with the first fifty rounds where the extractor somehow blew off the bolt and the extractor spring got mangled. Extractor looks a little chipped on the underside of the lug, too (as pictured). Gun was down after that, though fortunately I had a friend who also went to the range with me who's an MG-34 hoarder so I was able to borrow one of his spare bolt heads and continue shooting.

After that it was just experimenting with different booster cones and flash hider inserts. I have a flash hider that was "converted" to be a brake with a welded insert (because I live in Commiefornia), which the guy who did it for me said it would increase backpressure a little.

Apparently the reason why the extractor blew off my original bolt head was because I was overgassing the system using the BRP 308 diameter booster cone (I believe that's like an 8mm orifice), in conjunction with my "brake" cone. I also have a normal cone I got for testing and it seemed to cycle well with my friend's spare bolt (which I should mention also has a normal firing pin spring; my original bolt still had the TNW thicc machined spring which is ridiculously heavy to recock).

So I contacted TNW and they said send the bolt in so Lance can fix the extractor free of charge. Nice. I also decided to get a second spare semi auto bolt so I can have something as a backup in case my primary bolt goes down.

Was able to shoot about 300 rounds of .308 down the pipe. Some stoppages, sometimes it ran pretty well. I think it will require a bit more fiddling with the gas system but nothing blew up and no major issues or parts breakages aside from the extractor spring, I figure most of the issues will work itself out as soon as I get the extractor fixed and plop in a coiled full auto firing pin spring to reduce the cocking force necessary to cycle the gun. These guns are very sensitive to the backpressure generated by the booster cones, I’ve been told.
>> No. 108421 ID: bbee29
File 155539309119.jpg - (121.22KB , 632x685 , IMG_20190407_144343.jpg )
>extractor chipped
>increased backpressure
Yep that makes sense looking at where it broke. I'd always start with a more open booster because running the gun hard will put a lot of wear on the ejector pin and other components. It's pretty easy to put in a tighter booster for more gas if it doesn't cycle fast enough and fails to eject rounds but the gun will beat its parts out cycling too hard but still cycle until it spits out guts. As stated earlier in the thread, mine was very overgassed at first and ate an ejector pin in ~20 rounds so I think I stopped and lucked out before anything else broke.

I've also made progress on the TNW MG34 on my end.

So I've been learning that the cyclic rate is affected by more than just booster port. Mainly, the firing pin spring. Mine seems to need a stiff spring as anything less doesn't seem to hit primers hard enough. In turn that'll slow the action down and it should make ejector pins last longer. I also think my main recoil spring (the big one) is a little weak. The barrel return spring might also need to get beefed up but it does feel quite stiff so I'm not going to mess with it now. Needless to say, making a handful of boosters at various diameters is saving my butt in this process. I found that pencil-testing my firing pin spring tension worked well. Assemble the bolt, cock it outside the gun, balance a pencil on the bolt face, and push the sear in to release the firing pin. At least three feet straight up for a regular pencil worked for me, less than that and I had failures to fire from weak pin strikes in good PPU 8mm (not really hard primer surplus). During my testing, the sear ended up wearing so I ordered some high impact resistant S7 tool steel. I'll be making new semi-auto sears and sear rings (not sure what that part is called, it's what the TNW sear catches to cock the firing pin) from S7, it should hold up quite a lot better than the buttery soft TNW ones.

I've also found some original ejector pins with the wedge-shape cuts that did help ejection quite a lot. I've replicated the original and my replica ejectors function perfectly. I made them from drill rod and gave them a quick heat treat only in the rear, and not too hard. Just a little bit to prevent the pin from deforming when hitting the ejector plate. Picture related, the original is on the left. Despite the shittiness of my garbage chinese """metal""" lathe, it makes quick work of this kinda part and I just hand filed the rest of the features.

Other than that, stoppages were mostly belt related. The TNW 34 advances the belt as the bolt is moving forward, so there's energy lost from the main recoil spring simply from advancing the belt to ready a fresh round. As the bolt is then moving a bit slower, it can be slowed down too much during feeding if the link holds the round too tightly. I'm not sure why they did it that way, I would have thought that a system that advances the belt as the bolt is opening, taking advantage of the recoil power, and only advancing the pawls (very little force required) would leave the bolt with as much energy as possible to strip a round from the belt and push it in the chamber. As a result, mine seems sensitive to how tight the belt is on the actual rounds, this could be exacerbated by the old main recoil spring. When I find belts or specific belt links that feed well, I push a round through it with my fingers (no gun, just holding everything in my hands), and then check tension by comparing other belt links. They're often much too tight, and require very carefully prying them open just a tiny bit. I carefully pry them open with needle-nosed pliers, matching the case taper as carefully as I can, and testing with a round to get the right tension. I might make a tool for this that can pry the belt link to the right tension automatically as I've bought like 25 belts and most of them have links that are too tight. Like many guns, once the minor issues with gassing/springs are resolved, the rest of the troubles end up being shitty magazines or in our cases, belts that just aren't quite right. I suggest you have a go at feeling your belt link tension as I think it's one of the final things to square away before the gun gets really quite reliable.

it's nice having belts and starter tabs now but the issue is buying enough ammo to fill 25 belts f f f f f u u u u c k
>> No. 108422 ID: 6fe1bd
File 155543256466.jpg - (1.04MB , 1020x1920 , IMG_20190416_101740.jpg )
Here we go.
>> No. 108423 ID: 6fe1bd
File 155543285151.jpg - (1.17MB , 1381x1920 , IMG_20190416_101821.jpg )
Damn I suck at this freehand shit but this should be close enough. The optical comparator has seen better days so dimensions could be a tiny bit off, minor fitting by hand will likely be required.
>> No. 108425 ID: 4eaeff
File 155544186210.jpg - (51.49KB , 900x600 , MG34-GNPT-XX08-BKXX-4B37-2.jpg )
>So I've been learning that the cyclic rate is affected by more than just booster port. Mainly, the firing pin spring. Mine seems to need a stiff spring as anything less doesn't seem to hit primers hard enough. In turn that'll slow the action down and it should make ejector pins last longer. I also think my main recoil spring (the big one) is a little weak. The barrel return spring might also need to get beefed up but it does feel quite stiff so I'm not going to mess with it now. Needless to say, making a handful of boosters at various diameters is saving my butt in this process. I found that pencil-testing my firing pin spring tension worked well. Assemble the bolt, cock it outside the gun, balance a pencil on the bolt face, and push the sear in to release the firing pin. At least three feet straight up for a regular pencil worked for me, less than that and I had failures to fire from weak pin strikes in good PPU 8mm (not really hard primer surplus).

Are you using the thicc machined TNW spring or a coiled spring that was found in the original full auto MG-34? I was using the TNW spring in my gun for the first fifty rounds until the extractor on my original bolt blew off. It was lighting the ammo off fine (MKE 2014 kebab 7.62x51 NATO ammo ZQI brand), and when I swapped out the bolt body with my friend's spare, he used a coiled full auto MG-34 spring, probably one acquired from BRP Guns. I continued to fire with my reloaded 7.62 ammo using CCI #34 primers and the coiled spring had no problems lighting that ammo up. I didn't have any light strike issues.

I think I will probably go with the coiled spring going forward. It should be enough to light up the primers I use in my general purpose 7.62x51 reloads. The added benefit of having a less stiff spring is that the cocking force necessary to unlock the bolt under recoil is a lot reduced so I don't have to restrict the cone so much in order to get it to fully cycle.
>> No. 108426 ID: 6fe1bd
My TNW spring was shortened a little bit, but it's still not perfect. I would like to try a coiled MG34 spring, because so far the other springs I've tried short of the TNW were too weak.

I have ordered music wire and some compression springs from Mcmaster Carr. Perhaps an industrial spring will work, the dimensions are really quite close. I'll also be attempting to make a main recoil spring from theusic wire as I can't seem to find much up here for that. I'll be fiddling with all this soon but first I need to finish the sears.
>> No. 108432 ID: bbee29
File 155565223877.jpg - (227.45KB , 1274x967 , IMG_20190418_233258.jpg )
Aight so the S7 tool steel machined ok, but I don't really know what's the proper way to heat treat them.

What do?
>> No. 108434 ID: e6ec85
Maybe call TNW and ask for Lance, maybe he could tell you what Brinell hardness they do for their own sears?
>> No. 108437 ID: bbee29
As far as I can tell by scratching at the original with various metals, the original sear seems to be medium carbon steel in a mildly hard state. I've heard of the softness of sears from many owners so I'm not sure TNW even knows how hard their sears are supposed to be, and if they do, their quality control could use some improvements as I see no evidence of harness testing on the sear.

Even >>106836 had the same issue.
>> No. 108438 ID: e6ec85
If you decide to sell any of those sears LMK, I would be interested after you figure out how hard these things should be.

My friend who is knowledgeable about these TNW 34s said that the sear in my particular gun (built in 2018) has a third style of sear that he's observed so far, so it seems like TNW is still tweaking the sear design. I haven't had any slamfiring in my particular gun, either with the original machined firing pin spring or a coiled firing pin spring, FWIW.
>> No. 108440 ID: bbee29
I'll be testing them soon, I'm not considering selling anything unless I'm satisfied that it'll work well. I don't want to cause any unfortunate/expensive "malfunctions" by jumping the gun and selling stuff that might not be good enough.

Just trying to figure out how S7 likes its heat treatments. From what I can see, I don't think I have the equipment to heat treat it reliably, so I might have to send them out and have it done right.
>> No. 108443 ID: 51b0a9
You don't/ However you do have access to steels the Natzis only dreamed of, Even marginal shit like A2 was unheard of in the 40's.
>> No. 108445 ID: bbee29
I'd have to actually compare internals with a real MG34, but I know TNW has made changes to make their gun semi-only. Do correct me if I'm wrong, but in the original gun, the sear doesn't take the kind of beating that it suffers from the semi gun.

I might try the magnet dangle over a metal bowl full of oil. What could go wrong?
>> No. 108447 ID: e6ec85
File 15560416151.jpg - (22.87KB , 260x346 , 51Dem2MXu-L__SY344_BO1,204,203,200_.jpg )
There's actually a snippet from the Folke Myrvang "MG34 and MG42 German Universal Machine Guns" book that has a report from a U.S. Army-commissioned metallurgy report on a captured MG-34 and it reported that most parts of the MG-34 just utilized carbon steel and other steels that were absent nickel except for some few critical parts, such as the bolt, bolt rollers, and sear would be hardened and made from alloyed steel.

Interestingly the metallurgical report stated that the barrel was also made from basic steel, probably to keep costs of producing barrels low as they were considered readily-replaced consumables. I'll take a screenshot of the relevant pages of the book for your reference.
>> No. 108451 ID: 4eaeff
File 155626678728.jpg - (3.17MB , 4032x3024 , 20190426_011647.jpg )
As promised, here's the U.S. Army metallurgical of a captured MG-34, found in the Folke Myrvang book "MG-34 and MG-42 German Universal Machineguns".
>> No. 108452 ID: 4eaeff
File 155626684413.jpg - (2.47MB , 4032x3024 , 20190426_011703.jpg )
Not sure why the hell page 1 rotated but should be easy enough to rotate the page on your own.

Page 2
>> No. 108453 ID: 4eaeff
File 155626687336.jpg - (2.54MB , 4032x3024 , 20190426_011724.jpg )
Page 3
>> No. 108454 ID: bbee29
File 155628667598.gif - (507.47KB , 318x212 , my_human_of_african_american_descent.gif )
Thanks my dude.
>> No. 108457 ID: e153ed
This right here. Stuff nearly made my FN 49 beat itself to death
>> No. 108458 ID: e153ed
This right here. Stuff nearly made my FN 49 beat itself to death
>> No. 108459 ID: e56201
I personally don't give a shit about this particular info, but this is the kind of stuff that made this place great back in the day. People posting actual solid information.
>> No. 108462 ID: b224b5
File 20190426_195002.webm - (3.81MB )
My 34 seems to run well with my brake cone + 9.15mm booster. 11mm booster occasionally leads to stovepipe, which would indicate to me the bolt isn't traveling fully rearwards under recoil.

These things are gonna be bad for my wallet. Way too easy to shoot shit tons of ammo quickly.

Also, how do I tighten the rear AA sight? Seeing it bounce around under recoil kinda sucks. Maybe I'm missing a leaf spring or something underneath it because it just flops around.
>> No. 108463 ID: bbee29
I've heard 11mm is basically past the tolerance for open booster, I would suggest something around 10mm perhaps. It could be a bit more gentle to the parts. They're pretty simple to make if you have access to a lathe, but I don't think they're that expensive in freedomland, it could be worth it in the long run. You could buy a spare booster and drill it out incrementally larger to get the perfect boost.

I don't have the AA sights so I'm afraid I can't be much help there, sorry.
>> No. 108467 ID: bbee29
File 15568589157.jpg - (742.77KB , 1981x1385 , bowlettes.jpg )
Anyone have experience with this stuff?

Seems to be an FMJBT with a crimp groove, an exposed lead bottom, brass case, crimped-in berdan primer. There seems to be a faint (probably) laser etch on the case of the letter K followed by 8x57 IS. No headstamps.

Bullets measure a tiny bit oval at .3231 to .3234 off my Mitutoyo mic, and don't worry I didn't bother measuring the bullet I pulled out with the pliers.

Weighed 44.1 grains of some flake powder, advertized muzzle velocity from their test barrel is "2500ft/s", after checking some reloading manuals (Lyman, Barnes, Speer, Lee, Hornady, Nosler) that's not too crazy, a few manuals list some IMR powders (3031, 8208, 4064) doing about that fast from 24" barrels with that much powder. I know IMR is sticks and this powder is flakes, but I'm just trying to see if shit makes some kinda sense.
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