That_Baka

It's just following the provenance of any antique and what is the likely outcome.
If you are an evil spy organization like the KGB *ominous music* why do you care about decades old almost obsolete bolt action mil surps in the 1950s. And if one must need cover their trail for plausible deniability, why not use any of the millions of captured Mausers the Russkies had in inventory. And it's a Mosin. Gee. Even the densest CIA agent knows what side of the iron curtain they are made from.
It's not like its a damn U2 spy plane.

Ahaha, Don, my spamforce™® was faster than yours!
That video bothers me - his claims are not based on anything, really. He didn't mentioned his sources, or maybe i didn't watched it with needed attention.

I've field-stripped a spectre, and I was surprised at how crude it was.
 
Dunno how functional they are, but they're sure not pretty.
 
The magazine design is fucking rad.

That certainly looks like a weapon that would be carried by an anonymous henchman standing around in the background of a super villain's top secret lair. It's the sort of gun that says "I'm wearing a bright blue contractors helmet and silver coveralls but I'm not supposed to look directly at the camera while I shuffle around in front of this forklift". It's the sort of gun that is so imposing, a guy with a toupee and tuxedo armed only with a .32 caliber pistol can shoot me from the distance of most cricket pitches while I spray the Spectre sub-machine gun futilely from the hip causing sparks to fly from the sheet metal siding the hero is hiding behind. It's the sort of weapon that the aforementioned hero wouldn't even deign to pick up as he escorts the buxom love interest through the hanger vault of the top secret lair while he attempts to track down the aforementioned super villain, before an elaborate countdown sequence blows up a recognizable World Heritage Site with a stolen nuclear device.
 
Cool find though!

"I think radios should have those rails so you an fit on do-dads like bayonets, maybe call it the tactical radio" - Heckler & Koch 

Yakutia SOBR unit in Northen Caucasus and SR-3M "Vikhr" 9x39 mm automatic carabine.
 

Hardingush and GM-94.
 
Chechen Spetsnaz team "Terek" prepare to competitions in Jordan.
http://youtu.be/O6GQzSKn0Sk
 
"Terek" in Jordan.
http://youtu.be/NA0CIKtZM7Y
 
 
St.Petersburg FSB team "Grad". Those guys 2 years ago arrested one Islamists not far from my home. 
http://imgur.com/a/hji6q#2eeyE1u
 


 

 
From 1:36 you can see some interesting things. That training with "live obstructions" reminds Alpha training, which Larry filmed.

Claymore attached to the front rail will solve that problem, son.

Germans are a very literal people, and they got a bit confused when they heard somebody calling the radio their most effective weapon because of the indirect fire fragmentation capability.

Let's all take a trip back to the late 1970s and early 1980s.  This was the time of punk.  This was the time of despair.
 
Punk was all about minimalism; strip everything down to a few chords, wear clothes you fished out of a garbage can or made yourself and infect yourself with parasitic worms so that when you vomited on some other asshole in a fight, they got parasitic worms too.  It wasn't pretty, but it was cheap and it worked.
 
Punk was about to hit pistol design in a big way.  The aglockalypse was just around the corner.  The glock is the practical application of punk to the art of small arms design.  It's reminiscent of John Browning's early striker-fired design prototypes for the hi-power, only made out of plastic and missing half the parts.  Not pretty, but cheap and it sure does work.
 
The world was very different in the punk era.  Remember that in the United States, violent crime increased dramatically in the late 1960s.  In the 1970s they were still figuring out what to do about that.  They hadn't had a few decades for the idea that gunfights were just something that might happen day to day to sink in, so the art of practical handgun usage was in a pretty sorry state.
 
Or rather, practical handgun knowledge was in a hilariously bad state at the time.  I read through a police marksmanship manual from the late 1960s or early 1970s; it's like an infantry tactics manual written pre-WWI.  It's heartbreakingly naive because they hadn't seriously had to seriously think about the problem before then.  They had come from a more peaceful world, and were still getting their bearings in the grimdark of the 20th century.
 
This police marksmanship manual still taught the FBI crouch.  The FBI crouch is a sort of distillation of the WWII-vintage Fairbairn-Sykes theory of gunfighting, which emphasized speed over accuracy.  The idea behind the FBI crouch is that you crouch down so that you're harder to hit, and you sort of get your dominant arm that's holding the weapon into a repeatable, ergonomically neutral alignment with the rest of your body so that you can aim with your entire body.  As you can see, this isn't a shooting stance that allows you to use the pistol's sights.  In some variants of the stance, you cross your left forearm over your torso so that incoming bullets have that much more flesh to go through before they start hitting your vital organs.
 
Basically, it's the sort of theory of how to gunfighting that you might come up with in a society that, until recently, hasn't been doing a whole lot of gunfighting.
 
Everything was in a more primitive state than it is now.  Nowadays you can go into a gunstore and have dozens of brands and styles of pistol ammunition to chose from; hollowpoints of all descriptions line the shelves, each promising to kill people more dead than the next one.  Oh, and you can buy full metal jacket if you need something cheap for practice.  Back then, full metal jacket was the fancy stuff; the most common ammo was cast lead.  Also, cops weren't totally sold on automatic pistols until about halfway through the '70s, they still mostly used revolvers.  Also, almost nobody owned a handgun.  It was considered weird.  Owning a rifle or a shotgun was perfectly normal; what else are you going to go hunting with?  Owning a handgun was weird because handguns are for shooting people, and why are you even thinking about shooting at people you weirdo?  The laws and court precedent for self-defense cases were a lot different then too.  Formerly peaceful society, still coming to grips with the grimdark.
 
So, secret about Beretta; they basically want to make hunting shotguns and make up-scale hunting apparel.  They can't design automatic firearms actions to save their lives.  Whenever they have to make something automatic they rely on Germans to design the things for them.  The AR-70, for instance, was originally a joint design effort with SIG (SIG's evolved into the SIG-540/550 series).  The ARX-160 was designed by Ulrich Zedrosser, who, as you might surmise from his name is not Italian.  The Beretta 92 is the last in a line of Beretta pistols that started off basically as clones of the Walther P-38.
 
You can imagine it; Beretta in the 1970s doesn't really know what makes an automatic pistol a superior combat piece, although they've been making clones of the Walther action long enough that they can make them work very well.  Cops don't know how to gunfight either; all they know is that these automatics seems a whole lot easier to shoot yourself with than revolvers, so they're going to need some sort of super-duper double safety device.  Some want double action with a decocker, some want a safety as well, someone want a combined safety decocker...
 
So Beretta shrugs their shoulders and tries to please all these cop agencies.  Obviously, they're mainly going to be selling these things to cops and military and a very small number of weirdos.
 
Meanwhile, Jeff Cooper, Jack Weaver and a small but growing number of practical pistol competition shooters are figuring out how to actually fight with a handgun.  Meanwhile, in Austria, long-standing armament maker Steyr is about to get a nasty surprise when the Austrian Army holds a competition for their next pistol.

Where it gets really weird is when glock accidentally releases a new model that is simply a square, plastic cut-out of a gun. And nobody notices any change in unit effectiveness.

Do the three hakenkreuze on the turret signify that it has indulged three times in teamkilling? 

Is that the Bob Semple Tiger?

Inb4 next WoT premium  

That's no problem for a Russian army "restoration" team.

My personal experience was that the early Panzer IVs kick ass if you know how to use them. PzGr. Rot is a mini nuke, and there isn't much that can resist it. What can resist it is usually small vehicles vulnerable to crew losses from Hl 38B/C. The large internals and 5 crew members mean fairly good survivability if you aren't ammo-racked.
37mm guns are generally suffering.

RADIRS (Hydra 70 rocket pods, basically)

 

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. 

I'm going to take minor issue with the part of your thesis that characterizes US production as behind because it focused on forging the receivers. I say this, because the US had gotten extremely good at receiver forgings. You show an image of "M14" receiver production which is highly misleading, as it is in fact an image of the modern Smith Enterprises Inc machining process (from billet) of their M14 reproduction receivers. In reality, the M14 receive was formed from a very close forging. For comparison, here are some images of an original M1 forging:
 



 
This receiver forging obviously required additional machining to turn it into the finished product, but you can see the level of extreme detail conveyed to the blank by the forge: Even the cutout for the rear sight mechanism, and the feed area are forged straight into the receiver. As well, the details on the underside of the receiver are already beginning to show, such as the hollow where the bolt reciprocates, and the area for the magazine.
 
These forgings lost very little mass to become finished receivers, relative to what other forgings require (compare to the FAL receiver in your post above). In this way, they were extremely well production optimized.
 
Of course, it's true that the receivers still took some considerable machine time to finish (though much less than other forgings), and there were correspondingly efforts to reduce the cost of the weapons. Although M14 manufacturer Harrington and Richardson decided to make their rifles exactly the same way they were making M1s, Winchester and TRW both innovated new ways of turning receiver forgings into complete receivers. Winchester produced M14 receivers automatically, turning forgings into receivers via early NC machines. TRW in particular is notable for their procedure of using high precision forgings which were then cut by enormous chain broaching machines to finished dimensions.
 
Also, the rest of the M14 was production optimized as well. Looking back briefly at the Earle Harvey T25, which had been designed from the ground up to be producible in garages across the United States in the event of nuclear war (no, really), the M14 took a page out of this book as well and was extremely well-suited for distributed production, with almost all other parts besides the barrel, bolt, and receiver able to be cast in the small foundries which were common at the time. In fact, TRW produced only 11 parts for the M14, and outsourced all other parts production to other manufacturers, and were able to offer the M14 to the government at a considerable cost savings as a result ($79.45 per, compared to $95 per for H&R). H&R also subcontracted out most small parts of the rifle.

Question Six: Why was this thing so poorly suited for mass-production?
 
 
Let's look at the problems of mass-producing small arms in a little more detail.
 

Can you tell it from a javelin?
 
This is the receiver of a Mauser Gewehr 98/K98 rifle.  The receiver is responsible for containing the force of the burning propellant, which for a few ten-thousandths of a second is on the order of four tons.  The receiver thus needs to be quite strong, and along with the barrel it is the single most expensive portion of the rifle.
 
The receiver of the Mauser rifle is made of a forging of ordnance-grade steel.  This means that a billet of steel is heated until it is soft, but not molten, and then mashed in some gigantic mechanical hammers into a rough outline of the final shape like so:
 

 
After that the forging must be machined or milled.  In this step, various machine cutting tools are used to remove excess material.
 

 
The Mauser is generally held to be the best-engineered of the First World War rifles, but all other rifles from the period were of comparable construction.
 
During the First World War, all major combatants found out that their rifles were simply too damned expensive.  War planning had assumed that the next conflict would involve far fewer soldiers than it actually did, and planners had failed to anticipate the number of rifles that were lost or destroyed in the field.  All major combatants in the First World War learned this painful lesson, but to the Germans the problem was especially dire, as they were heavily reliant on foreign supplies of the alloys for making ordnance-grade steel.  To the Germans, reducing the amount of specialized alloys used in their rifles was a major strategic issue.  Most other nations had more reliable supplies of alloy raw materials, but reducing the cost of weapons and time needed to produce weapons was still a major concern, once the tempo and scale of modern warfare was understood.
 
The German solution was the STG-44, née MKb-42(H), which was the culmination of research into cheaper weapons that had been started in the 1930s.  The designers had realized that there really wasn't any way to make the barrel cheaper, but they could make the receiver substantially cheaper.  The STG-44 achieves the remarkable feat of having no ordnance-grade steel in the receiver whatsoever.  Additionally, much of the rest of the receiver was made of stampings.  Stampings are steel components made of sheet metal that is bent, cut and formed with hydraulic presses and dies.  Stampings are not only faster and cheaper to make than machined forgings (at least for large production runs, for smaller runs they are less economical), but they produce far less waste material that needs to be recycled.  Production volume can be increased enormously.  The changeover from the milled-receiver PPSh-41 to the stamped PPS-43 [Sturgeon edit: The PPSh-41 has a stamped receiver. I am not sure whether colli intended to say "PPD-40" (which was milled) and "PPSh-41", or something else]* allowed the Soviet Union to double the number of SMGs made per month during WWII.
 

An STG-44 receiver stamping
 
Most post-war small arms development focused on the use of stampings.  The Soviets had the greatest success: the AKM was a truly sublime piece of manufacturing engineering.  Western designers took a little longer to figure things out; of the first generation of Western combat rifles, only the CETME/G3 had a stamped receiver (though there were many stamped prototypes that simply didn't make it).  Also, the receiver stamping of the CETME/G3 is quite a lot more complex than that of the AK, and it is also heavier.  Still, while it failed to meet the high standard for production streamlining that the AKM achieved, it was a perfectly competent effort for the era.
 

And HK G3, showing some of the stages of turning raw sheet metal into the finished rifle.  Stamping the receiver of an HK rifle is a complex, multi-step process.
 
All that said, the milled Western rifles weren't completely hopeless.  While the use of a milled receiver in the FAL and the M14 was basically backwards and primitive by the 1950s, both of these rifles have reasonably small receivers.  So, while the steel still needs to be removed from the forging by the lengthy and laborious process of milling it off chip by chip, the total amount of milling that has to be done isn't that great:
 

In the FAL the receiver is kept compact in part because some of the moving parts are housed in the stock.
 

In the M14 the receiver is kept compact because many of the moving parts are outside of the receiver.  However, this makes them vulnerable to mud and dust.
 
At the same time, a private firm spun off from an aerospace company called Armalite had a different idea.  They constructed their rifle, the AR-10 primarily out of aerospace-grade aluminum and used an absolute minimum of high-grade steel where needed for strength.  Aluminum alloys have a higher strength-to-weight ratio than steel stampings, but in addition to saving weight, they solved the manufacturing problem as well.  Aluminum alloys, while more expensive than steel, were not in short or tenuous supply for any major power after World War Two, so they were unlikely to become a chokepoint for rifle production.  In addition, aluminum is much softer than steel, which permits much faster machining operations.  Thus, the aluminum receiver of the AR-10, while conventionally machined from a forging just like the rifles of the previous generation, did represent a viable alternative to sheet steel stampings for mass production.
 
Mass production is addressed at 3:28
 
So, you want to know what post-war combat rifle was designed without any thought of streamlined mass production whatsoever?  Yep, that's right, the EM-2.
 

 
Per the official records, the rifle was 35 inches long and had a 24.5 inch barrel.  The last inch or so (generously) of the rifle consisted of the buttpad.  However, we can also see that at least an inch and a half of receiver wrapped around the barrel past the bolt face:
 

 
So, the receiver of the EM-2 is at least eleven inches long.  The receiver of the FAL and M14 were both about eight inches long.  On top of that, the receiver of the EM-2 was much larger and voluminous than that of the FAL or the M14, as it completely encloses the bolt carrier and bolt carrier raceways and return spring, which is not the case in either of those designs.
 
An enormous amount of maching time would be spent in particular on the rear portion of the receiver, which is a large, hollow area where the bolt carrier reciprocates.  Much material would need to be removed here, and that would take a large amount of machine time.  Furthermore, this would be hard, expensive, ordnance-grade steel.
 
There is no indication whatsoever that this expensive, time-consuming receiver was ever considered an interim design.  Indeed, Enfield had already made arrangements with outside contractors to heat treat the gigantic receiver, as they apparently lacked the capacity to do so.  The .280 trial models sent to the US for competitive testing were considered "semi-production," and the changes made after the 1950 US trials were extremely minor and did not involve changing the construction of the receiver.
 
Interestingly, there is a British document from 1951 that acknowledges that the EM-2 was more expensive to produce than the FAL.  It then proceeds to give a variety of silly excuses for why this is the case (e.g. that it was made to higher standards and was intended to be accurate enough to double as a sniper rifle, and that front-locking weapons are inherently more expensive to make).  However, this document declines to give exact costs.
 
It is clear, however, that the EM-2 was really very poorly suited to mass production.
 
 
 
*The anecdote about the PPS-43 vs the PPSh-41 is taken directly from the Collector's Grade book on the STG-44.  As Sturgeon points out, the PPSh-41 is also stamped, so I have no idea WTF they are actually talking about.  Possibly the PPS-43 was simply better production optimized.

There are a few things to note about the Cody Museum's EM-2:

-As Sturge notes in his blurbette on TFB, this is a later 7.62x51mm weapon.
-The charging handle is coated with bakelite, which is something I have not seen in other pictures of EM-2s.  One of the complaints that was raised in the US trials was that the charging handle of the EM-2 tended to burn the user.  It's likely that the bakelite coating is an attempt to rectify this.
-I was totally going to try and field strip this sucker to get a look at the internals, and when we were asking for permission to do so, we were told that there was a gigantic blizzard incoming and everyone had to leave the museum.  In a display of excellent judgment, Sturgeon and I then decided to start driving on the highway for Montana.

There's quite a bit more to add to SH's only unironic bash thread. Some excerpts from things I've written, starting with the Modern Intermediate Calibers episode on the .280:
 
Two short articles I did on the .280 and NATO rifle competitions:

http://www.thefirearmblog.com/blog/2016/02/28/the-return-of-weekly-dtic/
 
http://www.thefirearmblog.com/blog/2015/01/28/rifle-competition-us-vs-uk-1950-dtic/
 
Something from my notes for Light Rifle V - coming soon™:
 
 
I have never handled an EM-2, but I know four or five people who have not only handled examples, but disassembled them (Those being: Ian McCollum, Matt Moss, Jonathan Ferguson, Trevor Weston, and maybe one or two others I correspond with). It's worth noting that at least three of those people believe that the EM-2 could not have been mass produced economically in the configuration of the test rifles - the receiver was simply too big and complex a workpiece.

Here at Sturgeon's House, we do not shy from the wholesale slaughter of sacred cows.  That is, of course, provided that they deserve to be slaughtered.
 
The discipline of Military Science has, perhaps unavoidably, created a number of "paper tigers," weapons that are theoretically attractive, but really fail to work in reality.  War is a dangerous sort of activity, so most of the discussion of it must, perforce, remain theoretical.  Theory and reality will at some point inevitably diverge, and this creates some heartaches for some people.  Terminal, in some cases, such as all those American bomber crews who could never complete a tour of duty over Fortress Europe because the pre-war planners had been completely convinced that the defensive armament of the bombers would be sufficient to see them through.
 
In other cases though, the paper tiger is created post-facto, through the repetition of sloppy research without consulting the primary documents.  One of the best examples of a paper tiger is the Tiger tank, a design which you would think was nearly invincible in combat from reading the modern hype of it, but in fact could be fairly easily seen off by 75mm armed Shermans, and occasionally killed by scout vehicles.  Add to this chronic, never-solved reliability problems, outrageous production costs, and absurd maintenance demands (ten hours to change a single road wheel?), and you have a tank that really just wasn't very good.
 
And so it is time to set the record straight on another historical design whose legend has outgrown its actual merit, the British EM-2:
 

 
EM-2ology is a sadly under-developed field of study for gun nerds.  There is no authoritative book on the history and design of this rifle.  Yes, I am aware of the Collector's Grade book on the subject.  I've actually read it and it isn't very good.  It isn't very long, and it is quite poorly edited, among other sins devoting several pages to reproducing J.B.S. Haldane's essay On Being the Right Size in full.  Why?!!?!!
 
On top of that, there's quite a bit of misinformation that gets repeated as gospel.  Hopefully, this thread can serve as a collection point for proper scholarship on this interesting, but bad design.
 
Question One:  Why do you say that the EM-2 was bad?  Is it because you're an American, and you love trashing everything that comes out of Airstrip One?  Why won't America love us?  We gave you your language!  PLEASE LOVE ME!  I AM SO LONELY NOW THAT I TOLD THE ENTIRE REST OF EUROPE TO FUCK OFF.
 
 
Answer:  I'm saying the EM-2 was a bad design because it was a bad design.  Same as British tanks, really.  You lot design decent airplanes, but please leave the tanks, rifles and dentistry to the global superpower across the pond that owns you body and soul.  Oh, and leave cars to the Japanese.  To be honest, Americans can't do those right either.
 
No, I'm not going to launch into some stupid tirade about how all bullpup assault rifle designs are inherently a poor idea.  I would agree with the statement that all such designs have so far been poorly executed, but frankly, very few assault rifles that aren't the AR-15 or AK are worth a damn, so that's hardly surprising.  In fact, the length savings that a bullpup design provides are very attractive provided that the designer takes the ergonomic challenges into consideration (and this the EM-2 designers did, with some unique solutions).
 
Actually, there were two problems with the EM-2, and neither had anything to do with being a bullpup.  The first problem is that it didn't fucking work, and the second problem is that there was absolutely no way the EM-2 could have been mass-produced without completely re-thinking the design.
 
See this test record for exhaustive documentation of the fact that the EM-2 did not work.  Points of note:
 
-In less than ten thousand rounds the headspace of two of the EM-2s increased by .009 and .012 inches.  That is an order of magnitude larger than what is usually considered safe tolerances for headspace.
 
-The EM-2 was less reliable than an M1 Garand.  Note that, contrary to popular assertion, the EM-2 was not particularly reliable in dust.  It was just less unreliable in dust than the other two designs, and that all three were less reliable than an M1 Garand.
 
-The EM-2 was shockingly inaccurate with the ammunition provided and shot 14 MOA at 100 yards.  Seriously, look it up, that's what the test says.  There are clapped-out AKs buried for years in the Laotian jungle that shoot better than that.
 
-The EM-2 had more parts breakages than any other rifle tested.
 
-The EM-2 had more parts than any other rifle tested.
 
-The fact that the EM-2 had a high bolt carrier velocity and problems with light primer strikes in full auto suggests it was suffering from bolt carrier bounce.
 
 
As for the gun being completely un-suited to mass production, watch this video:
 
 
 
Question Two:  But the EM-2 could have been developed into a good weapon system if the meanie-head Yanks hadn't insisted on the 7.62x51mm cartridge, which was too large and powerful for the EM-2 to handle!
 
Anyone who repeats this one is ignorant of how bolt thrust works, and has done zero research on the EM-2.  In other words, anyone who says this is stupid and should feel bad for being stupid.  The maximum force exerted on the bolt of a firearm is the peak pressure multiplied by the interior area of the cartridge case.  You know, like you'd expect given the dimensional identities of force, area and pressure, if you were the sort of person who could do basic dimensional analysis, i.e. not a stupid one.
 
Later version of the British 7mm cartridge had the same case head diameter as the 7.62x51mm NATO, so converting the design to fire the larger ammunition was not only possible but was actually done.  In fact, most the EM-2s made were in 7.62x51mm.  It was even possible to chamber the EM-2 in .30-06.
 
I'm not going to say that this was because the basic action was strong enough to handle the 7x43mm, and therefore also strong enough to handle the 7.62x51mm NATO, because the headspace problems encountered in the 1950 test show that it really wasn't up to snuff with the weaker ammunition.  But I think it's fair to say that the EM-2 was roughly equally as capable of bashing itself to pieces in 7mm, 7.62 NATO or .30-06 flavor.
 
 
Question Three:  You're being mean and intentionally provocative.  Didn't you say that there were some good things about the design?
 
I did imply that there were some good aspects of the design, but I was lying.  Actually, there's only one good idea in the entire design.  But it's a really good idea, and I'm actually surprised that nobody has copied it.
 
If you look at the patent, you can see that the magazine catch is extremely complicated.  However, per the US Army test report the magazine and magazine catch design were robust and reliable.
 
What makes the EM-2 special is how the bolt behaves during a reload.  Like many rifles, the EM-2 has a tab on the magazine follower that pushes up the bolt catch in the receiver.  This locks the bolt open after the last shot, which helps to inform the soldier that the rifle is empty.  This part is nothing special; AR-15s, SKSs, FALs and many other rifles do this.
 
What is special is what happens when a fresh magazine is inserted.  There is an additional lever in each magazine that is pushed by the magazine follower when the follower is in the top position of the magazine.  This lever will trip the bolt catch of the rifle provided that the follower is not in the top position; i.e. if the magazine has any ammunition in it.
 
This means that the reload drill for an EM-2 is to fire the rifle until it is empty and the bolt locks back, then pull out the empty magazine, and put in a fresh one.  That's it; no fussing with the charging handle, no hitting a bolt release.  When the first magazine runs empty the bolt gets locked open, and as soon as a loaded one is inserted the bolt closes itself again.  This is a very good solution to the problem of fast reloads in a bullpup (or any other firearm).  It's so clever that I'm actually surprised that nobody has copied it.
 
Question Four:  But what about the intermediate cartridge the EM-2 fired?  Doesn't that represent a lost opportunity vis a vis the too powerful 7.62 NATO?
 
Sort of, but not really.  The 7mm ammunition the EM-2 fired went through several iterations, becoming increasingly powerful.  The earliest versions of the 7mm ammunition had similar ballistics to Soviet 7.62x39mm, while the last versions were only a hair less powerful than 7.62x51mm NATO.
 
As for the 7mm ammunition having some optimum balance between weight, recoil and trajectory, I'm skeptical.  The bullets the 7mm cartridges used were not particularly aerodynamic, so while they enjoyed good sectional density and (in the earlier stages) moderate recoil, it's not like they were getting everything they could have out of the design.
 

note the flat base
 
In addition, the .280 ammunition was miserably inaccurate.  Check the US rifle tests; the .280 chambered proto-FAL couldn't hit anything either.

Oooh!  Good choices, and yes, there are many victims and clones that I did not mention.
 
You've got to wonder WTF was going on with Colt at that time.  Basically all of their automatic pistol design introductions were flops.  Rather than grit their teeth and unfuck them, they let themselves get chased out of the automatic pistol market... just in time to miss the explosion in pistol sales thanks to changes in CCW laws across most of the USA.
 
The XD has an interesting departure from the Glock where the slide actually rides on this big, machined steel insert that's pinned into the frame.  But otherwise, yeah, it's a Glock with a bunch of unnecessary crap added to it.
 
The 320 goes one better; it has a stamped insert that (it looks like from pictures) acts as the slide rails and also holds the fire control group and acts as the serialized component.  Otherwise it's fairly Glocky.
 
The idea of using a metal insert as the serialized component that has the slide rails on it is clever, and would give a manufacturer a small edge over the Glock in the US marketplace.  It's harder to injection mold a polymer frame with metal inserts in it than it is to just injection mold a solid polymer frame.
 
Furthermore, if the polymer frame is the serialized component of the gun, the ATF requires that the serial number be on a metal plaque molded into the frame.  Most firearms manufacturers don't have their own injection molding equipment, and most injection molding companies don't have a firearms manufacturing license.  So the ATF has to grant a variance in these cases.
 
By making the slide rails/FCG/serialized box a separate, pinned-in piece, SIG bypasses the FFL variance paperwork and the difficulty of molding the metal inserts into the frame.
 
It's not an enormous advantage, but at this point anyone doing anything that's actually cleverer than Glock is noteworthy.
 
 
 
The insides of the Strike One are surprisingly un-Glocky:
 

They made a big deal about the differences in the operating mechanism in one of their early presentations:

 
It's a little similar to how the P-38/M92 lockup works; there's an extra little piece that locks the barrel to the slide.  Instead of pivoting around the pitch axis like the P-38's locking piece it slides up and down.  Mechanically it's fine, although I don't think it has enormous practical advantages over the Glock design.  The big problem with their locking design is that it has a bunch of tiny corners that need to be machined inside the slide.  To make these tiny corners they use electrical discharge machinging (EDM), which is insanely precise and also insanely expensive.
 
So it's not a very good design from a cost-control standpoint.  Surprisingly, they've kept the price to about 1.5 Glock 17s.