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As a historian I can agree that the road of WTF may have been short in the grand chronological scheme of things but it more than made up for it in the number of lanes the road had. 

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Well I wrote my Master's dissertation on it, so I've been hands on with the rifle and I've done archival research into UK govt. records. It's difficult to say when exactly it 'died' because it depends on what you take a the final nail in the coffin. The very final death of it was Churchill and the Conservative Party's return to government in late 1951. His meeting with Truman in Jan '52 ended all hopes of progress with the EM-2. But arguably the project stalled when the ammunition compromises began and the US were still disinterested. From an engineering standpoint the rifle needed a lot more work, Nate and I have discussed several times how the EM-1 probably had a better chance of becoming a suitable service rifle. It was a serious contender for unilateral British adoption certainly if we had decided to go it alone (Churchill very much saw the big picture and did not want us to do that). It is possible Canada may have followed us which may have cancelled out some of the production capacity concerns. 

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4 minutes ago, mjmoss said:

Well I wrote my Master's dissertation on it, so I've been hands on with the rifle and I've done archival research into UK govt. records. It's difficult to say when exactly it 'died' because it depends on what you take a the final nail in the coffin. The very final death of it was Churchill and the Conservative Party's return to government in late 1951. His meeting with Truman in Jan '52 ended all hopes of progress with the EM-2. But arguably the project stalled when the ammunition compromises began and the US were still disinterested. From an engineering standpoint the rifle needed a lot more work, Nate and I have discussed several times how the EM-1 probably had a better chance of becoming a suitable service rifle. It was a serious contender for unilateral British adoption certainly if we had decided to go it alone (Churchill very much saw the big picture and did not want us to do that). It is possible Canada may have followed us which may have cancelled out some of the production capacity concerns. 

 

Excellent!

 

Do you, by chance, have a link to this dissertation?

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I'm afraid it's not available electronically at the moment :\ I did suggest it to them. I'm in the process of improving it, more learnt since I finished it 18 months ago. Nate is doing good stuff on the US angle though. Hopefully we can team up and put something together. 

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Christ, what a question! I shall try and keep it short - there are both political and technical stories running parallel. 

 

It had potential, that much is clear. It was pursued over the EM-1 because it was slightly further along the development phase. Once Britain put all their efforts into the EM-2 the project was ambitious, more so than anything else at the time. Calibre was supposed to be selected by a panel of ballistics experts (Ideal Calibre Panel) but another working committee's suggestion of .280 was selected over the ICP's recommended .270 - a mistake. Not that .280 isn't a decent round for what it was intended to do. Politically this is all within the context of the emerging NATO alliance when they didn't know what they were aiming to achieve - standardisation proved to be impossible on all but some ammunition and some equipment. 

 

The US, for their own reasons (which are worth a book in themselves) disliked .280 and made concerted efforts (at least in British eyes) to put NATO powers off .280. Meanwhile in the UK the sitting Labour party use EM-2 as a flagship rearmament program, Chruchill's Conservative party against this and believe in preservation of the Anglo-US alliance at all costs. Once Labour lose next election (just 5 months after 'adoption' of EM-2 as the Rifle No.9) the Conservatives move to axe rifle program. Some evidence to suggest Churchill may have used it as a bargaining chip to secure a senior NATO naval command position for UK (this may have occurred during the Jan 52 meeting with Truman).

 

The project stagnated due to US Ordnance unwillingness to compromise and UK political indecision. Add into this a lack of funding and a design which needed more refinement for general production and you have a complicated narrative. 

That's the summary view and I feel like I have probably left out a lot - its been 18 months since I worked on EM-2 properly, other projects have taken priority. But its a fascinating rifle and its development and downfall are equally interesting. I've not doubt Nate can fill some of the inevitable gaps!   

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1 hour ago, Collimatrix said:

 

 

I disagree.  The program essentially ran from what, 1949-1953, or thereabouts?  It was a fairly short road of WTF.

 

The program began immediately post-war. So it was really eight years.

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At the time the Labour government was in the middle of setting up the National Health Service and the Welfare system, these were key election pledges which had swept them into power - they were rightly focused on. However, with the Korean War and the Chief of the Imperial General Staff warning that Western Intelligence estimated the USSR would be in a position to launch another conflict within a decade it was decided that the UK's rearmament program should be sped up. As per the CIGS plan the first five years after WW2 would be spend on R&D and then the next 2 and 3 years would be spent putting UK on a wartime footing with new tech. You have to remember in 1950 UK was in massive debt to the US, was rebuilding infrastructure and manufacturing capability and putting in place the NHS. While the economy was recovering there was not money for all the defence programs with nuclear weapons development, Royal Navy rearmament (the RN shrank rapidly after the war), the RAF needed new jets (through a wonder of procurement they ended up with 3 different V-force bombers) and missiles were becoming key for both aerial and AA use (something Britain actually led on for a while).  So while the EM-2 or IW project wasn't under funded it was tightly funded, it just didn't have the high priority that say a new tank like the Centurion did. 

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2 minutes ago, Sturgeon said:

 

The program began immediately post-war. So it was really eight years.

 

Yeah, the IPC was set up in '46 IIRC, first of the EM designs were in prototype form by '47. Even before '46 the Armament Design Department was looking at ways to meet the 1944 Infantry weapon specification put out by the War Office. 

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1 minute ago, Collimatrix said:

 

Dugelby quotes it as starting in 1947, but this might include work on the Korsak EM-1.

I believe the Korsac to essentially be a war time design that remained in development to around 1946, by which time Thorpe's EM1, Janson's EM2 and Hall's abortive EM3 were being looked at. The Korsac is not part of the IW program which began late 46/47 - would have to dig out my notes to confirm exact dates. The timeline of the project is one that needs to be set out clearly, I think it would really help to have a proper chronology. Korsac and the IW program are part of a wider UK military and design community's fascination with the bullpup concept which I haven't been able to pinpoint when it began yet. 

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On 7/30/2017 at 7:05 AM, Collimatrix said:

Further Further notes on the Cody Museum's EM-2:

 

-There were, discounting the first five hand-built prototypes, there were four batches of EM-2s built.

 

-The first twenty rifles were made in the .280 caliber.  These rifles were made by Chambons Tool Company as well as RSAF Enfield.  These were the weapons used in the American competitive trials against the T25 and early FAL prototype in 1950.  Even at this early date, these rifles were considered "semi-production," i.e. aside from small tweaks, the design was already frozen.

 

-A further batch of six rifles was made by BSA in 1951-1952 in the .300 T65 caliber.  These also incorporated small changes based on experience from the American trials.

 

-Another batch of fourteen rifles was made by RSAF Enfield in the finalized 7.62x51mm NATO cartridge.  The Cody Museum's rifle is number nine from this batch of fourteen.  It does not appear that these rifles were subjected to much testing.  This is also the configuration of the rifle that was "adopted" by the War Office as Rifle Number 9.  If Winston Churchill had gotten completely pissed and forgotten to rescind the Labor government's idiotic order that the EM-2 be adopted, the rifle would have been adopted in 7.62x51mm, not .280!

 

-Oddly enough, the politicians did not seem to be aware of this fact.  There was intense political debate on the merits of Britain adopting their own .280 ammunition vs. the American 300 caliber, but by the time this debate was held the EM-2 had already been re-designed for .300 caliber ammunition!

 

-A final ten rifles were made in Canada by Canadian Arsenals Limited in 7mm Compromise (7x51mm) before the entire EM-2 program was cancelled in 1953.


Don't forget the four HV-series rifles made by Chambons.  They were originally divided evenly between 7x49mm (2nd Optimum) and .30 T65.  HV-1 was later rechambered from 7x49mm to the .30 T65, and later yet, converted for the legacy .30-06.

FWIW:  The T65-chambered BSA rifles ran from #1 to #10, of which six were located in the Pattern Room collection.  There were apparently fifteen 7.62mm EM2 made by RSAF-Enfield.  Note that the serials ran from EN100 to EN114.
 

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On 7/31/2017 at 2:23 PM, D.E. Watters said:

Is the EM2 receiver an entirely machined piece, or is it merely a machined section solely for the barrel trunnion and locking abutments, encased in a stamping?  Say like a StG44?

 

I think so.  The portion forming the bolt carrier raceways and the magazine well is milled for sure:

 

uysUl0q.jpg

 

You can see how the material continuously changes thickness around the ejection port, and how the case deflector changes thickness from bottom to top.

 

However, there does appear to be a seam between the locking area and the rest of the receiver:

 

LFubj5P.jpg

 

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On 7/31/2017 at 3:23 PM, D.E. Watters said:

Is the EM2 receiver an entirely machined piece, or is it merely a machined section solely for the barrel trunnion and locking abutments, encased in a stamping?  Say like a StG44?

 

The upper receiver (minus FCG, which I am not sure about) is 100% machined.

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57 minutes ago, Sturgeon said:

 

The upper receiver (minus FCG, which I am not sure about) is 100% machined.


Dang.

That said, perhaps this was only meant for the prototype runs?  You wouldn't want to mill out a bunch of sheet metal forming dies just to have the receiver configuration change.

Note that when Gene Stoner fabricated his AR-12 prototype, the upper receiver was actually machined to look like it was stamped.  The goal was to eventually transition to stampings once the basic design was settled.

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Just now, D.E. Watters said:


Dang.

That said, perhaps this was only meant for the prototype runs?  You wouldn't want to mill out a bunch of sheet metal forming dies just to have the receiver configuration change.

Note that when Gene Stoner fabricated his AR-12 prototype, the upper receiver was actually machined to look like it was stamped.  The goal was to eventually transition to stampings once the basic design was settled.

 

I've looked into this pretty extensively, and I'm quite sure there were no such plans.

 

IIRC, they figured they would just forge and then machine the receivers. I'll check with Matt though.

 

The whole program was incredibly immature relative to the US effort (which itself still managed to drag because lol Army).

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From my research the only fore-thought regarding mass production I saw was a number of letters to 2 fibreglass specialists about the manufacture of fibreglass stock furniture rather than wood and wood veneer used on the prototypes. As regards to the simplification of manufacturing I don't recall seeing any in-depth plans - I just don't think they got to that point. Both the bolt and receiver would have required quite a lot of machine operations per unit. The FCG could have been made from stamped parts but that is about it. The milling needed for the bolt and the locking flaps were unavoidable but perhaps something could have been done to reduce machine time for the receiver. There was a weight limit established by a WO spec that the ADD/ADE worked hard to be close too.  

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1 hour ago, mjmoss said:

From my research the only fore-thought regarding mass production I saw was a number of letters to 2 fibreglass specialists about the manufacture of fibreglass stock furniture rather than wood and wood veneer used on the prototypes. As regards to the simplification of manufacturing I don't recall seeing any in-depth plans - I just don't think they got to that point. Both the bolt and receiver would have required quite a lot of machine operations per unit. The FCG could have been made from stamped parts but that is about it. The milling needed for the bolt and the locking flaps were unavoidable but perhaps something could have been done to reduce machine time for the receiver. There was a weight limit established by a WO spec that the ADD/ADE worked hard to be close too.  

 

The Dugelby book mentions something, offhandedly, about research into powder metallurgy that was abandoned.  Any idea what that was intended for?

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3 hours ago, mjmoss said:

I don't recall seeing anything about powder metallurgy in the documents I looked through. It may well have been considered, interesting prospect. 

 

"6. Powder metallurgy was contemplated but the project was cancelled before further research was done."

 

-Pg 61

 

On 7/31/2017 at 2:23 PM, D.E. Watters said:

Is the EM2 receiver an entirely machined piece, or is it merely a machined section solely for the barrel trunnion and locking abutments, encased in a stamping?  Say like a StG44?

 

 

The EM-1 would have had a stamped receiver with machined inserts.  EM-1 seems to have been the more conceptually sound design for this reason.

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In general, the execrable L85 series of weapons is not related to the EM-2.  Both rifles were bad, but they were bad for completely unrelated reasons.  There is one thing, however, that the EM-2 did pass along to early prototypes of the L85.  This was a pathological and uniquely British fear of flash hiders.

 

Flash hiders are terribly useful things to have on the muzzle of a rifle.  In addition to enormously reducing the visible flash at the end of the muzzle, they can also double as mounting points for rifle grenades and blank firing adapters.  They help protect the crown of the barrel, and they can even save a barrel from bursting if someone slips and jams their muzzle into the dirt, as flash hiders are a wider internal diameter than the bore and have holes in them, which allows the propellant gas to flow harmlessly around the obstruction.

 

That's a fairly long list of advantages for basically no disadvantages, so the majority of rifle designers have taken it for granted that their weapons will sport a threaded muzzle with some sort of flash hider, brake, compensator or what have you screwed on to the tip.  In addition to the advantages above, screwed-on muzzle devices can also be easily replaced if someone invents a better one, or if someone slips, falls, and mashes the muzzle of their rifle into a concrete pad.  To anyone designing military rifles it was very clear that they really ought to have threaded muzzles.


Except the British.

T8qOks7.jpg

If you look carefully at this picture of the XL-64 prototype, you can see that there is no seam between the barrel and the flash hider.  That's right; the flash hider is machined into the barrel itself.

 

The completely irrational British hatred for threaded-on flash hiders began with the EM-2 program.  The majority of EM-2s were never equipped with flash hiders, and it was generally accepted (e.g. during the American competitive trials) that it did not need one.  The enormous 25 inch long barrel gave enough volume for the propellant gas to expand and cool that the EM-2's flash signature was naturally low.

 

Other rifles of the period, not being so blessed, required threaded on flash hiders.  Again, this wasn't at all a bad thing, but for some reason the British arms designers didn't see it that way and flipped the fuck out about the idea of flash hiders.  This excerpt from a salty missive from then Labour MP Woodrow Wyatt sums up the British perspective:

 

Quote

The new British EM-2 is six inches shorter than the Belgian rifle [i.e. the FAL].  It is three quarters of a pound lighter.  It can fire double the rate of aimed shots per minute.


But that is not all.  Because the barrel (not the overall length) of the Belgian rifle is shorter than that of the British it is bound to give off a great flash when it is fired and that gives away the soldier's position to an enemy.

Presumably the Belgian rifle will need some sort of device to hide the flash at night.  This will make the rifle about another pound heavier and mean that the soldier has to carry another piece of loose equipment.

 

 

Total.  Insanity.

For the record, the shipping weight of a long FAL flash hider is 4 ounces, and an A2 flash hider is 2 ounces.  Flash hiders are not attached and detached willy-nilly, getting them on and off requires a vice, a wrench and some elbow grease.  But for some reason, the idea that flash hiders are heavy, detached pieces of gadgetry just waiting to get lost occurs several times in period British documents on the development of the EM-2.

Having identified a completely imaginary problem, the engineers proceeded to come up with an adequate solution:

K4netcO.jpg?1

 

And that is how the British machined-in flash hider came to be, until sanity (partially) re-asserted itself and the XL-70 was given a threaded muzzle.

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      One further problem facing the AVT was ensuring the transportability of the new tanks by the various trucks, ships, and railcars that were in use at the time by member nations. The solution was to limit the weight of the new tank to 40 tonnes, enabling it to be transported by the majority of surplus wartime infrastructure.
       
      The resulting hull design was highly convergent with, but distinct from the British Centurion tank. The armor plates were to be rolled, heat-treated, and cut to shape by industrially capable member nations with the industrial capacity, and then shipped along with automatic welding equipment, if needed, to member nations for assembly. Each welded part assembled together using dovetails - like a cardboard model - to improve the strength of the welds, allowing for somewhat expedited welding practices. The turret ring race and other senstitive contact areas were finished before the plates shipped. When assembled, the hull used a series of mounting rails for engine and transmission, which approximated very nearly the modern "powerpack" concept, albeit in a much less space-efficient form. The driver's position was accommodating, with appreciable space as well as adjustable controls and seating, and power-assisted steering levers and shifter.
       
      Armor on the hull consisted of a two three-inch plates joined at a 60 and 45 degree from the normal, attached to side plates two inches thick set at an angle of twelve degrees, like the Centurion. Top and bottom armor plates were one inch thick, while the rear armor plate was 1.5" thick. Like the Centurion, there was provision for .25" thick standoff plates mounted to the side of the hull, encasing the suspension.
       
      The hull was to be furnished with automotive components in-situ, so there was no standard engine or transmission. However, most studies were done with either the British Meteor engine and Merrit-Brown Z.51.R transmission of the Centurion, or the AV-1790 engine with CD-850 transmission of the T40 experimental US medium tank. Special mention, however, should be made of the design study of the tank using a Ford GAA engine and syncromesh transmission from an M4A3 Medium, intended as a backup configuration in the event that a member nation could not obtain more modern engines and transmissions. In this configuration, the mobility of the tank would be significantly decreased.
       
      Suspension was provided via a series of mounting points to which suspension elements could be attached. The "default" suspension configuration was for an individually sprung Horstmann derivative, but the design accomodated both single and bogied forms, as well as internal and external torsion bar, Bellevile washer, and volute spring methods of suspension. Track pitch, width, and design were likewise left up to member nations, but most early scale models used standard US 6" pitch 24" wide T81 tracks.
       
      Ancillary components, such as stowage boxes, lights, fuel tanks, and other minor details, were to be produced by the receiving nations, with stamping equipment and technical know-how distributed as needed. 
       
      With all of the allowed variation, AVT realized it would need to publish an "engineering guide" to the new tank design, by early 1950 somewhat uncreatively christened the "NATO Medium Tank". This was accomplished with the first trials of automotive pilots, and "AN ENGINEERING GUIDE TO THE NATO MEDIUM TANK" was published by ORO on July 21st, 1950, and distributed to member nations. As the document only detailed the dimensional and production aspects of the tank, it was not considered a security risk, as member nations couldn't possibly leak any sensitive information from it that they did not already possess.
       
      By 1950, the first mild steel turret mockups had been created, giving two of the automotive pilots a "proper" look, even though they were no more combat capable than before. The turrets were cast in a single piece, and fitted with a 90mm high-and-low velocity gun based on the British 20 pdr but utilizing experience gained from the American 90mm series of cannons. It was determined that for member nations, the most common type of shot available would be solid APC shot. Because of this, a high velocity conventional AP round would be needed to deal with anticipated Soviet vehicles. The resulting round fired essentially the same T33 AP shot as the 90mm M3 gun, but at a much higher velocity of 3,200 ft/s. Testing revealed the round could penetrate a 100mm RHA plate at 60 degrees from normal 80% of the time at 500m. This was considered, initially, sufficient to defeat the anticipated armor of Soviet medium and heavy tanks.
      In order to allow more fragile, and thus higher capacity HE and utility (smoke) shells, ammunition was also developed for the gun that used a foam-lined, reduced volume case loaded with a smaller charge. This high explosive round produced 2,100 feet per second with its unique 22 pound shell, loaded with 2.6 pounds of Composition B high explosive. The technical data packages for these two types of ammunition were widely disseminated to member states, for their local production.
       
      The new 90mm gun was also compatible with any projectiles for the older M3 series of cannons, including HEAT and HVAP. Further, it was expected that the cannon would serve as the basis for a new 100-120mm gun, designed to fire a new generation of HEAT and APFSDS projectiles.
       
      Also included with the armament were three unity periscopes for each crewman, a single-plane stabilization system for the main gun, and a gunner/commander cowitnessing system. The turret had two ready racks of five rounds a piece, with additional ammunition stowage planned to be in the floor of the vehicle, and adjacent to the driver.
       
      The turret was cast with 3.5-3.6" all around armor, improving to six inches at the front. A large, wide mantlet/gun shield of 6" thick was provided, partially to help balance the gun in its cradle. The turret ring was 74".
      NBC protection was available through a "kit" modification that was distributed to member nations upon request.
       
      Specifications, NATO Medium Tank:
       

       
      Crew: 4
      Dimensions
      Weight: 39.4 t
      Length (Hull): 7.2 m
      Width: 3.4 m
      Height: 3.05 m (without roof MG)
      Armament
      Main armament: 90mm T104E3/M56
      Caliber length: 62
      Tube length: 5.60 m
      Tube life: 500 shot
      Secondary armament: 1 × M1919, M60, MAG, MG3, etc GPMG
      Cannon ammunition: 65
      MG ammunition: 3200
      Elevation: +25/-12
      Penetration with T53 Shot, 10.9 kg at 976 m/s:
      100 m: 22.2 cm
      500 m: 20.0 cm
      1000 m: 17.9 cm
      2000 m: 14.3 cm
      Armor
      Upper Hull: 76.2 mm / 30 °
      Lower Hull: 76.2 mm / 45 °
      Rear Hull: 38.1 mm / 90 °
      Hull Roof: 25.4 mm
      Hull Floor: 25.4 mm
      Turret Mantlet: 152.4 mm / 90 °
      Turret Front: 152.4 mm / 90 °
      Rear Turret: 90 mm / 90 °
      Turret Roof: 50.8 mm
      Mobility
      Engine: Depends on variant, often AV-1790 w/ CD-850 transmission or Meteor with Merrit-Brown Z.51.R transmission. Variant with Ford GAA and syncromesh transmission also trialled.
      Displacement: Depends on variant
      Gears (F / R): Depends on variant
      Power to weight ratio: Depends on variant
      Top speed: Depends on variant
      Suspension: Depends on variant
      Fuel storage: Depends on variant
      Range: Depends on variant
      Track width: Depends on variant
       
       
    • By SirFlamenco
      Hi everyone, first post here 
       
      I stumbled across this video : 
       
       
       
      It’s super dense polyethylene with a neutral buoyancy core for impact resistance. It weights only 4 pounds, so for weight effiency it’s around 3 times better than ar550 and 4 times better than other ceramics ballistic plates, AND that’s while including the water, which I doubt add any bulletproof capabilities. 
       
      Is it just me or does it sound a bit fishy?
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