The Korsac EM1 - a British/Polish Bullpup FG-42

Armament Research Services (ARES) is a specialist technical intelligence consultancy, offering expertise and analysis to a range of government and non-government entities in the arms and munitions field. For detailed photos of the guns in this video, don't miss the ARES companion blog post:
armamentresearc...
The Korsac EM-1 (not to be confused with the Thorpe EM-1, which is a completely different rifle) was a bullpup light machine gun based on captured examples of the German FG-42 patatroop rifle. It was developed between 1945 and 1947 by a team led by Polish refugee designer named Korsac.
It was chambered for the 8mm Mauser cartridge, and used an 18 round magazine adapted from the ZB-26. The operating mechanism was closely copied form the FG-42, as were many elements of the rifle's controls, including the capability for firing from an open bolt in fully automatic and from a closed bolt in semiautomatic. Unlike the FG-42, it used a short stroke tappet type gas piston, and had a detachable barrel. Ultimately only two examples were built, and only one of those (the one in this video) was completed to firing condition. It suffered from reliability problems in semiautomatic mode, and was quickly sidelined in favor of the other development projects ongoing by 1947. However, many lessons from its development would be put into the EM-2 rifle.
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[@MaxB00M]

I like how we came to the point where Ian casually uses a fg-42 for reference

[@Tallmios]

According to his LinkedIn page, he works at ARES as researcher.

[@wierdalien1]

Tallmios this is in leeds

[@joemontgomery6658]

And on the ARES website

[@mcramen4488]

I can't even tell how much I love this comment. Yes we are in that point.

[@peterthinks]

You're probably the only guy on the planet who can walk into any museum and say "Mind if I take apart some of your irreplaceable one of a kind firearms?" and not get kicked out.

[@marcothommen2484]

:-D

[@slb797]

AND disassemble them

[@ZacharySkan]

@@slb797 he said "take apart" in the comment.

[@531greyghost]

He is the best guy today there is to display firearm museum pieces

[@TheTuttle99]

@@slb797 yeah! Take apart AND disassemble them!

[@sgta101]

This is probably one of the best action designs for bullpup. There is no need for a connecting trigger wire, and the firing pin connected to the gas piston makes it even more elegant imo.

[@Tunkkis]

Why did they put a bayonet lug on a light machine gun? Was there a Japanese person on the design team?

[@SilentRazor1uk]

Up until 1923, and somewhat until the later assassination of a Japanese Prime Minister in 1931, they (the Japanese) was quite closely aligned with ourselves, it was only after the 'Control' clique from the Army stole/co-opted & coerced power from the Diet & Emperor, that EGB/BC/UK lost what little remaining influence left over from after the 1923 treaty.

[@betaich]

The original FG-42 was intended as what we would call now a battle rifle. German doctrine back than was that every rifle needed a bayonet for close quarters. So it wasn't a pure light machine gun. It was supposed to fill the role of a rifle (far accurate shots), of an LMG (suppressive fire) and as a sniper rifle, when equipped with a scope (a ZF-42). The bayonet was a requirement from the Luftwaffe for the rifle design.

[@Tunkkis]

betaich I was joking about the EM-1 being an lmg bring equipped with a bayonet lug, because the Japanese had those.

[@betaich]

Eetu Tunkkari, I thought as much, right after I hit the send button, because I remembered the video on something like that from Ian.

[@MrBubbaSkeeter]

Sometimes you just gotta stab a few people

[@Sheerwater909]

So much British bullpup potential and it turns into the L85 -A1. Oh dear.

[@fritzkuhne2055]

John Brooks lol thought the same

[@edithdodds190]

it looks like a battering ram for a door

[@bendover9862]

Design by committee was one of the reasons British industry started failing. The SA-80 family was designed by committee, you can polish a turd but it will still be a turd. It was wrong to issue that piece of shit to troops, it should have been dumped 30 years ago when it was clear to everyone that the platform was a failure.

[@wierdalien1]

Ben Dover it is a good rifle now.

[@bendover9862]

It barely passes certain standards. The weight of the thing alone means it is not a good rifle, too heavy with terrible balance.

[@GruSzabolcs]

It's seems almost impossible that You can disassembly almost - who am I kidding, EVERY - firearms in the world. You are amazing Ian. Thanks for this amazing channel, your hard work in educating us in firearms, and the overall quality of your videos.

[@USSEnterpriseA1701]

That flash hider looks exactly like the one off of the Lee-Enfield Jungle Carbine. I'm willing to bet they used some of the same tooling to make it and it looks like it takes the same bayonet as well. I'm sure that commonality of tooling and some of the accessories was meant to be a selling point for this, just like the US intended with the M1 and M14. Funnily enough, the M14 receiver was so different from the M1 (probably because it's slightly shorter and narrower) they had to get new tooling anyway.

[@havareriksen1004]

If not for parts commonality, they probably used the tools and parts available to use dierctly or to copy, like all the EM rifles copied other rifle designs.

[@kombokil]

I love on this chanel that You talk really clearly. I don't need subtitles to understand you. :) Greetings from Poland.

[@awse93]

Still a better rifle than the L85A1

[@phileas007]

Maybe our definitions of "perfectly fine" aren't quite identical...

[@xmm-cf5eg]

A stick with a shotgun shell on the end of it is a better rifle than the L85. These guns actually got worse as development time went.

[@marcothommen2484]

Still a better lovestory than "Twilight"......

[@matthayward7889]

This is one of those videos, that, if I didn't know any better I would swear Ian filmed especially for me 👌🏻

[@marcimcfly9313]

I think the reason for changing the unlocking direction of the bolt is that they flipped the action upside down, so that they cold have a bottom feeding gun without the gas piston being in the way while keeping the ejection port on the right side of the gun

[@user-ns3vs3bp3e]

Can't work out if this is a monstrosity or a thing of beauty

[@mattdickson2]

123 456 i vote thing of beauty

[@ongjunhong]

It's both.

[@retroicdescent]

123 456 It's a monstrous thing of beauty.

[@StarkRaven59]

It can be and is both.

[@drasiritzbir]

But it is without a doubt a joy forever!

[@sae1095hc]

Hey Ian! Do the Royal Armouries have any examples of the Besal, the low cost, stamped, emergency backup LMG to the Bren? It wasn't really needed as Bren production was adequate to the task. I think it qualifies as a Forgotten Weapon.

[@JonathanFergusonRoyalArmouries]

We do! I'm sure Ian will consider it for his next visit :)

[@dogsnads5634]

Do you have a Taden as well?

[@Menace-Mikey]

I believe he did a video on the BESAL already.

[@Meph648]

Hello Ian, those aren't interrupted threads but simple geometry lugs. On the barrel, they would have been turned as grooves and then a second machining operation on a milling machine to make the interruptions. On the inside of the receiver, there are a few options, aside from the seam line like you pointed out. Simplest is making a thread down in the receiver with an extended tap, and making a threaded portion that would then be later installed to have the female interrupted lugs. If they didn't do that, they could make an internal grooving tool that fits into the receiver bore fairly snugly, and has adjustable cutting bits like an expanding reamer. Obviously the latter isn't very feasible, but it is possible to do. I love your videos, keep up the great work!

[@DirtyHairy1]

Thanks once more for presenting us one of these exotics. Without you and a platform like KZbin, these highly interesting historical designs would be buried under miles of bureaucratical nonsense from an interested individual.

[@techno_tuna]

damnit ian I am trying to sleep

[@visionist7]

Me too

[@nomad5215]

This man has stolen more hours of sleep than insomnia ever could

[@arthurbretas2003]

So am I

[@clickbaitable9578]

Bruh same

[@cadendouglas6332]

Jesus even three years later

[@wewillrockyou1986]

I really like the idea of moving the sear position to where the trigger is, this could actually be a way to get rid of the sloppy triggers bullpups tend to be plagued with.

[@roempoetliar7995]

The things that makes it unreliable in semi probably Too much of a mass and too little distance and those 2 springs just barely enough without making too heavy to cock open

[@WildBillCox13]

Wow. How very cool. Love the FG42 and am utterly impressed with this evolution of the piece into a more 'modern" configuration. Thanks for posting, Ian!

[@serceew3326]

just finished my morning work out routine, time to learn some old gun knowledge.

[@legopirate3000]

damn you are left

[@serceew3326]

Isak den vise so what? I'm for the right to bear arms too as long crazies can't get them

[@legopirate3000]

i didn't really mean to point out anything about guns, but while we are on the topic, how do you plan to know if a person is "crazy" or not.

[@serceew3326]

Isak den vise a thorough background check that would include psychiatric and criminal records.

[@legopirate3000]

seems legit

[@DudeNumberOnePlus]

The opposite rotation of the bolts is due to gas system positions. On FG its under the barrel, with Korsac above - but on both you want the extractor to be rotated to the right side of the weapon where the ejection port is.

[@nathaniel5756]

It makes me so happy when you come to England! Keep it up your channel is easily the best firearms channel on youtube

[@jeffreytam7684]

Makes sense for them to use the ZB mags. Considering the designers were East European, they would probably have some knowledge of their design, if not experience with them. Well you could argue Central Europe, but either way, my point is that the Poles on the design team would almost certainly have been exposed to Czech designers, and the service cartridge in both countries was 7.92X57, IIRC.

[@tobiashagstrom4168]

Good thing the Armament Research Services wasn't around during WW1, or Wonder Woman might've gotten confused.

[@Tracks777]

Great content

[@MrMonkeybat]

Interesting way of combining the a striker with the gas piston and combining open and closed bolt operation did not know that about the FG 42. Also avoids they usual transfer bars attached to the trigger on the later bullpup. I wonder how well the an FG 42 chamber for an intermediate cartridge would handle compared to other assault rifles.

[@stevethomas5849]

Thank you Ian for introducing me to a rifle that I didn't know, that existed if only in an experimental role.

[@ap1s2k78]

gorgeous brilliant design. elegant and simple. so cool. wondered how they did the switch from o.b. to c.b. and now I know!

[@enscribe]

That trigger is genius for a bullpup. Has anyone adapted that type of mechanism to operate a firing pin instead of the the whole bolt assembly? Thanks for sharing.

[@acbthr3840]

Ian, how is the trigger pull on this gun? I'd imagine its pretty darn crisp considering the way the trigger is linked to the action. Wonder why more bullpups don't use a system like this.

[@sword7166]

Most other bullpups don't use this kind of trigger because it really only works with the specific way an fg42 fires, as most other closed-bolt rifles are hammer fired

[@tedbruise4954]

This rifle is honestly beautiful to me.

[@ФилиппЛыков-д8е]

Curiously, the bolt/bolt carrier for FG-42 was borrowed by Germans from the Lewis LMG. As is noticed in the book "FG-42. Death from above": "...our story comes full circle".

[@conradsz]

Thank you for giving credit to the Polish engineer 🇵🇱

[@JustIn-op6oy]

Considering that strange sear connecting bar setup, I wonder if that allows for potential for a better trigger pull than most bullpup firearms.

[@jeffreytam7684]

Interesting that they also made sure to keep the inline buttstock. It may make the EM-1 even uglier, but I guess the British (or Poles, I suppose) saw the value of this feature, especially when dealing with a powerful cartridge like 8mm Mauser.

[@piritskenyer]

Question: what would happen if someone charged the weapon while set to ful auto but then switched the fire selector to semi? Would the bolt drop and chamber the round, would the bolt stay back and then drop when the trigger is pulled, or would it lead to some other outcome? Cheers

[@siouxsettewerks]

I guess (read "I hope") the secondary Single shot sear would catch the transfer thingy.

[@piritskenyer]

So basically when you switch over to semi, the auto sear drops, the semi sear rises and the transfer frame falls forward? So if you do it slow enough, you get and uncontrolled discharge by way of the transfer frame riding over the not-yet-high-enough semi sear?

[@thegoldencaulk2742]

That's an interesting question. Only real way to find out is to get a real FG-42 and try it with snap-caps.

[@beavisbutt-headson3223]

I would assume that the switch is set up so that at any point in time one of the sears is lifted unless the trigger is pulled. (i.e. 2nd sear lifts before 1st one drops on switch) So, it'll drop shut when switching from full auto to semi auto (semi auto sear rises first, then full auto sear drops and bolt goes forward). No idea about semi auto to full auto. Maybe the full auto sear can also catch on this T-shaped cutout that the semi auto sear engages with?

[@phileas007]

There are videos of the FG-42, I believe even our lord and saviour has one where he demonstrates this very principle ...

[@samrussell4065]

What a combination of elegant weaponry and missed opportunity... A LSW version of the EM1 .280 in full-power chalibre: that would have been a good combination for its day.

[@zendell37]

I like how all the early bullpup rifles looked so sleek and futuristic. Almost raygun level. Modern ones all seem so built up of plastic.

[@avva4090]

Curious as to why the rifle did not fire semi-auto consistently. Did the Mauser 8MM not produce enough force to fire the bullet as well as reliably cycle the bolt to the semi-auto locking position with the additional kit to make the bullpup config. work? It would make sense because the FG-42 did not have that in its design spec. Maybe the recoil spring was too heavy? Or maybe it was some other mechanical problem? Someone care to explain? Also: the Brits had this monstrosity and somehow managed to create an even uglier rifle in the L85. Impressive.

[@acbthr3840]

The design just didn't give enough spring pressure to the last little bit of travel I suppose. Would have needed to make a much stronger spring, thus mucking up other parts of the operating mechanism, or go back and tweak the length/weights of all the parts

[@wierdalien1]

Lord_Avvakum L85 A2 is pretty leave it out.

[@sthenzel]

It´s got nothing to do with the cartridge power, that had long down its job, the bolt was already closed, the main spring was already released except for the last half inch. The main spring also has pretty much no word in accelerating the firing pin (not in semi, that is), this is done by the firing pin spring. But - for cycling by hand, the gunner has to compress the firing pin spring which pushes the bolt against the locking surfaces, this produces friction which makes the first bit of the pull quite hard. So the firing pin spring must not be too heavy.For the gunner this may not be too much of an issue, but maybe for the gas tappet, which has not that much of a piston stroke. A slightly longer piston stroke would have been a way around that, but could that have been incorporated in this system?

[@equalitis]

Lord_Avvakum You need to re-examine that part of the video because I think you just misunderstood what was happening in the action. In semi-auto, the bolt assembly is locked forward only a few centimeters away from fully closed, so the recoil spring is nearly fully extended and therefore providing little pressure for the firing pin to strike with. In full-auto, the bolt is locked towards the back (open), so the recoil spring is under significantly more pressure. Each shot in full-auto is therefore going to lock the action at a point where the recoil spring can provide most of its power, while each shot in semi-auto is going to lock the action at point where the spring cannot provide anywhere near the same amount of force.

[@jimvandemoter6961]

Ian, once again you surprised me. I thought bullpups were a more recent idea, like from the 70's and onward. When, what was the first bullpup, and who made it?

[@ForgottenWeapons]

The first that I am aware of was the British Thorneycroft, shortly before WW1.

[@bobsteruk714]

Forgotten Weapons Ian, what is the origin of the term bullpup?

[@hazakdds7366]

Thanks Ian.

[@hekkenschutz]

Thank you Ian!

[@Szejski]

10:01 In Britain even the bolts rotate in the opposite direction than in the rest of Europe ;D

[@3.2Carrera]

What a design!

[@OrangeAmped]

That is a super cool gun.

[@Ctulhu911]

Amen!

[@highlandoutsider]

GunJesus lmao loving your work

[@Destilight]

The bolt rotates counter-clockwise because korsac was probably left handed. And i can assure you that it's by far the most reasonable reason.

[@mineral410]

would love to see a modern take on this rifle

[@fuzzydunlop7928]

My head cannot suss out this title. o.O This inspires a question - why hasn't anybody taken advantage of that sexy muzzle-device from the FG42?

[@elijahaitaok8624]

Fuzzy Dunlop word has it that they designed better ones

[@madmartigan185]

Fuzzy Dunlop I'm certain I saw a Rifle on this channel that had one, can't remember what it was called tho.

[@fuzzydunlop7928]

You have my attention, Elijah.

[@fuzzydunlop7928]

What sort of contemporary muzzle brakes do you think do it better?

[@LuisLopez-zh9kh]

Bullpup FG-42 in LMG form instead of a shaved off automatic rifle. this is the stuff dreams are made of.

[@Frob25]

The bolt, op rod/firing pin setup looks like bit of a kick back to the Lewis gun.

[@TalladegaNight]

These guns being in england are both probally deactivated, and that is painful to think about

[@uhmgunnagitchyuh]

The other big design difference is Korsac put the gas system above the barrel. I guess while he was modifying that he ended up changing the rotation of the bolt too. I think he should have kept the op rod on the bottom like the krauts did. Then he wouldn't need that giant sear slide thing dragging down the whole system.

[@alfeovaldez8066]

beautiful FG42

[@jamesbrisendine]

I think I'm watching this for the first time. Weird, i have watch a billion vids but don't recall this one.. That being said, this gun is pretty rad. I think if the makers had more time and money they could've gone even farther and possibly made a more reliable rifle.

[@amateursmith1697]

I need this

[@matejmatej3554]

awesome video you got my both thumbs up you explained that gun very very good there was a time when I was having a few questions and few seconds later you had the answers love your content keep up the good work would love to support you on patreon but I'm unemployed Slavic man greetings from Slovenia hope you visit us sometime in the future (I don't have ability to pay through internet I just don't trust the online payment)

[@balham456]

Wow. In 1946 the British army could have had a state of the art assault rifle. Instead, they plodded on with the same weapon they had in 1914 till the mid 50s.

[@Kav.]

The Enfield No4 was not the same as the SMLE of 1914. Also no.

[@baronmagroth758]

this was Way cool a dummy like me can see both sides of the coin ... well done and Thank you

[@diamondflaw]

I choose to hear "ARES" as a "Harry's" said with a British accent. It just makes it more fun somehow.

[@ghost963cz]

They could make the grip any shape they wanted and they chose this.

[@LadyAnuB]

How many staff members at the National Firearms Centre clench their butt cheeks when Ian says "We're going to take this apart" when dealing with their collection of single example firearms? :)

[@notthestatusquo7683]

Is there a particular reason why the double sear concept where you can chose from firing from an open or closed bolt more popular today?

[@roempoetliar7995]

I'm not good at physics and math but or even engineering. From the eyes of a chair gun nerd; The things that makes it unreliable in semi probably Too much of a mass and too little distance and those 2 springs is just enough without making it too heavy to cock open If someone crazy enough let me design a gun using this system. I would probably lay the gas system sideway, like Steyr Aug and have the saperate firing pin/striker+rod on the other side making it a bit lighter but well, I never design machine or even shoot gun before so might not even work. this is just my ramblings of a armchair gun nerd

[@RemusKingOfRome]

Movie "Dunkirk" should good next month.

[@bramveneman]

Almost 200k views and only 30 dislikes. If that isn’t a record!

[@tassiehandyman3090]

Follow up comment - I suggest to you that Mr korsac was left handed, and he made the bolt turn the other way JUST BECAUSE HE COULD!!!

[@alexvogel610]

Is there some sort of barrel cap on that FG42? I'm not seeing a muzzle...

[@josephleinhauser6130]

Ian, this may be a dumb question, but during wartime do international patent rights no longer apply? I know the United States has some run in with the Mauser patents when they produced the 1903 Springfield, but it seems that during war patents aren't recognized/ respected. This would apply to the Cold War period as well as the soviets pretty much took western products and reverse engineered them in some cases down to the serial numbers.

[@FlyingSnake110]

Is there any mechanism that prevents weapon from firing while switching from semi to full auto? From the video it seems that selector "switches" sears and that it should fire. Or it would fire after being bumped from the back...

[@JoachimElmesioo]

How much less accuracy would you get from firing this in full auto compared to semi auto, as it locks well before the bullet is fired, or does the inaccuracy problems from a open bolt full auto rifle come mostly from all the mass being shifted around or something else?

[@caryk3028]

Do you think the magazine holds less because it originally fed from the top and therefore required a beefier follower to overcome gravity?

[@pcka12]

Ian there is a Pathe film of new firearm trials, as well as EM2 it shows a new machine gun (I don’t think it is this one). I wonder if you have found the actual weapon in the pattern room, and whether you might make a film about it? Thanks

[@calvingreene90]

For a bullpup it must have an excellent trigger. But it needs a little more spring.

[@stevenboelke6661]

Aside from balance, which is more comfortable to hold?

[@jasonhw00]

So will that semi-auto sear take a lot of impact abuse from the BCG since it stops the forward momentum of the whole BCG and Bolt?

[@ccfmfg]

If the Open Bolt /Closed Bolt Trigger Group worked on the FG42, why could it not be made to work on the Korsac EM-1 British/Polish Bullpup FG-42?

[@seoulkidd1]

If you watch the movie Theirs is the glory you'll see British Para used this gun but it was top loaded

[@SmokinCoal]

Is anybody else looking at how small the rear end of this bullpup looks? Maybe it’s kind of balanced weight wise. I like it

[@Kav.]

It's very balanced, but it's not as small as it looks. It's just compared to other bullpups it looks smaller. The EM-1 Korsac itself is actually a very large gun.

[@ReidMerrill]

An FG42 with a quick change barrel in .280 would have been a really good bren replacement.

[@Kav.]

Er, why? We had Bren guns in .280 which would have been a good bren replacement.

[@thomaslaustsen4034]

do you think a production model would have had a quick change barrel

[@Niafi11]

14:33... Or they had the Reciever done, and the Barrel Lock Threads Milled, and they were like..."Oh, Damnit. We didn't just do that, did We? Son of a Bitch. Well, Just Cut it down the middle there...and so on"

[@Taurevanime]

Ian, considering this rifle unlike other bullpups doesn't use light flimsy bits of metal for the transfer of it's trigger but rather large heavy pieces of solid metal, how did the trigger feel? Better or worse than other bullpups. Of course this is a trials gun and museum copy, nor did you get to fire it, but I am curious if this is a better trigger design for a bullpup.

[@Efreeti]

That twin sear trigger mechanism is weird but interesting. What other guns have that?

[@jojo3549]

Why is there a change with Open bolt and closed bolt in semi and full Auto? I guess close bolt in semi means less Vibration and better aiming!? But why change that in Full Auto?

[@reonthornton685]

I'm no expert but I imagine that overheating was a concern as the barrel wasn't exactly a quick change like a full size Machine Gun, as well as it simply being easier in that time period with certain designs.

[@sword7166]

Closed bolt guns when used in full auto can have a malfunction called a cook-off where the barrel gets so hot that a round sitting in the chamber can ignite and fire without the primer being touched. A lot of machine guns are open bolt for this reason

[@Internetspaceships]

Question : Do you relube the guns before you put them back together?

[@Crimson_Mando]

Hell no!! It will eat away the metal on the working parts faster; clean and oil before you use doing so can keep the barrel in better condition for longer.

[@karolpofficial9307]

His name is Roman Korsak.

[@lordcaoliki2168]

Would not the FG-42 technically be the first assault rifle as opposed to the Stg-44? Wasn't it the select fire configuration in a lighter package what makes it an assault rifle along with an intermediate cartridge?

[@hockeytero]

Lord Caoliki 7.92x57 is not an intermediate cartridge.

[@lordcaoliki2168]

Makes sense, cheers

[@lordcaoliki2168]

I think it's a full rifle cartridge

[@lordcaoliki2168]

Indeed, but the whole point of an intermediate is that it's the half between a pistol and a rifle calibre. I suppose its closer but still not quite there yet.

[@pietaushamburch6128]

Yeay! A lefty hand bolt mechanism just for Gun Jesus! Must be heaven on earth! :D

[@Viewerds]

My home town

[@zendell37]

"this isn't progressing as well as the others". Bruh...it's a bullpup FG42. You can't progress that well from near perfection. Although one major improvement I could see would be a non reciprocating bolt handle.

[@Kurzula5150]

Expect to see replicas of this at steampunk conventions.

[@nikolapetrovic4814]

I reminds me of the bozar from New Vegas.

[@kunicross]

Can't remember if I've ever seen Ian using gloves... What will we all do once Ian has covered and mud tested and used every firearm ever created in a 2 gun match? Will redoing all the videos in 360° 8k video be enough?

[@Niafi11]

Operating Gas Block Rod?

[@nigelpeppin1219]

Should have just adopted the entire FG-42.

[@tomaszsiudak2807]

The name was Korsak, not Korsac.

[@mrplague9881]

I would love to see that firing.

[@George_Doc]

Dont forget about "Like".

[@CitizenSmith50]

Who needs single shots (ie semi-auto) on a light machine gun anyhow? Surely that's what assault rifles or sniper rifles are for?

[@MrLoobu]

Jesus this is dope as fuck.