WI: 7.62x51mm never becomes NATO standard

Excuse the necromancy, but there's one question I had been meaning to ask.

I noticed that 6mm-6.5mm calibers seem to perform quite well. The Imperial Japanese Army used 6.5 x 50 mm Arisaka in the Type 38 rifle and several MGs. From some cursory searching (and I'm no expert on small arms), it seemed to be regarded as a decent rifle round but lacked the energy to be a satisfactory MG round.

How did it stack up compared to, say, .270/.280 British/6.5 mm Swede?
 

Deleted member 1487

Excuse the necromancy, but there's one question I had been meaning to ask.

I noticed that 6mm-6.5mm calibers seem to perform quite well. The Imperial Japanese Army used 6.5 x 50 mm Arisaka in the Type 38 rifle and several MGs. From some cursory searching (and I'm no expert on small arms), it seemed to be regarded as a decent rifle round but lacked the energy to be a satisfactory MG round.

How did it stack up compared to, say, .270/.280 British/6.5 mm Swede?
It as certainly more powerful than the .270 British, but nearly comparable to the more powerful versions of the .280 British. Depending on what load for the 6.5 Swedish was used it was either about as powerful or significantly less powerful. Overall it was roughly in the same realm as the .280 British and 6.5 Swede. The .270 British was significantly less powerful, but easier to control for an infantry hand weapon on automatic. With a decent muzzle brake though, like the FG42, it could have been ideal in a 1950s style battle rifle provided it had a more aerodynamic bullet. Arguably it was pretty ideal for a LMG and maybe even a SAW, certainly a DMR, but it was probably underpowered for a MMG. IIRC the issue with it, besides the range in a open field of fire, was it's relative lack of penetration of cover in the jungle fighting in the Pacific vs. the US .30-06.
 

Deleted member 1487

Now thanks to Gun Jesus playing with an original FG-42 on full auto today I wish I could see one in 6.5 Arisaka. It would have been legendary. I wonder if say the FG42 had been chambered in 6.5x57 Mauser (ballistically the same as 6.5 Swedish) with say a lower weight SmE Lang bullet whether the US would have changed their minds about 6.5mm calibers. Since the FG42 was apparently respected by the US enough that they combined it's design with elements of the MG42 to make the M60, if it were in 6.5mm perhaps that might have gotten US Army attention about the benefits of that caliber in combat.

In case anyone was interested in the FG42 experience I mentioned:
 
Love that video. And if anything could have got the us army past the whole "we only want .30 cal ammo" I do think a 6.5 mm fg42 could have been it
 

Deleted member 1487

Love that video. And if anything could have got the us army past the whole "we only want .30 cal ammo" I do think a 6.5 mm fg42 could have been it
If they found a way to mass produce it too the US Army might have had a battle rifle-gasm and might have realized the hope of replacing the BAR in actual practice and create a viable battle rifle.
 
I
If they found a way to mass produce it too the US Army might have had a battle rifle-gasm and might have realized the hope of replacing the BAR in actual practice and create a viable battle rifle.
I
wanted to say that it’s to expensive to build but the truth is you just need a then modern Kahn like factory with sufficient single use machine tools (to allow for the use of relatively unskilled workers) and spam them out by the tens of thousands. Jobs a good un.
 

Deleted member 1487

I wanted to say that it’s to expensive to build but the truth is you just need a then modern Kahn like factory with sufficient single use machine tools (to allow for the use of relatively unskilled workers) and spam them out by the tens of thousands. Jobs a good un.
Not even, they had a stamped steel version in the works. If they also converted it to roller delayed blow back....
Edit:
Actually would the roller delay system have been able to work with the side magazine? I have the feeling the roller in the bolt on the side of the magazine would get somewhat impeded when the bolt retracts past it.
 
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CalBear

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Early adoption .... say 1950 ...... would have been better for Canadian soldiers fighting in Korea.
OTL They were equipped with bolt-action, WW2-vintage rifles, but really, really, really needed more automatic weapons to stop Chinese human-wave tactics.
They could have purchased, probably for a nickel apiece, surplus U.S. M-1 and had a semi auto that would hit with lethal enegry out to a couple thousand yards.
 

Deleted member 1487

I
I
wanted to say that it’s to expensive to build but the truth is you just need a then modern Kahn like factory with sufficient single use machine tools (to allow for the use of relatively unskilled workers) and spam them out by the tens of thousands. Jobs a good un.
Come to think of it, knowing the US style they probably would do a Kahn factory and mill out the weapons like the expensive lighter alloy first version of the FG42 (with V2 handgrip and bipod placement):

It would be like BARs for everyone. With 6.5mm 120 grain round it would be more controllable than the EM-2 rifle.
 

Deleted member 1487

One last thing. One way to prevent the 7.62 NATO being adopted, which is outside the scope of the OP, is for the .276 Pedersen to have been adopted pre-WW2. As it would have the performance already to match or exceed the 7.62 NATO round there is no point in the wider bullet making a comeback.
 
One last thing. One way to prevent the 7.62 NATO being adopted, which is outside the scope of the OP, is for the .276 Pedersen to have been adopted pre-WW2. As it would have the performance already to match or exceed the 7.62 NATO round there is no point in the wider bullet making a comeback.
i'm going to disagree with you on that,
.276 Pedersen isn't able to replace 30.06 in belt fed guns, and switching the mmg's/gpmg's over to 7.62 after the war makes sense, it would also be possible if something like 7mm-08 was adopted post war for that role

this does make the post war adoption of something like .270 Brit for rifles far more likely
 

Deleted member 1487

i'm going to disagree with you on that,
.276 Pedersen isn't able to replace 30.06 in belt fed guns, and switching the mmg's/gpmg's over to 7.62 after the war makes sense, it would also be possible if something like 7mm-08 was adopted post war for that role

this does make the post war adoption of something like .270 Brit for rifles far more likely
In LMG/MMG roles? Sure it is. HMGs were already .50 cal. The 7mm Pedersen round maintained energy and accuracy better than the 7.62 NATO due to the bullet designs and sectional density. The 7.62 NATO round was designed to sort of match the performance of the M2 Ball .30-06 in a shorter case, which was worse than the .276 Pedersen round at longer ranges. In fact where the .276 already bested the .30-06, the 7.62 was actually even lower powered.
http://wintersoldier2008.typepad.co...n-were-pipsqueak-cartridges-in-compariso.html
By 400 yards the .276 was already surpassing the .30-06 round in velocity and shortly beyond that retained retained energy. In terms of MG use then the .276 was the superior cartridge.

The Brits were considering switching to .276 Pedersen pre-WW2 if the US did, so they might well have converted pre-WW2 themselves too, which would butterfly the .270/.280
 
I'm not sure whether it was suggested before, but how about this: Germans make the FG-42 in 6.5mm Italian? Should've been more controlable in automatic fire, and it is early enough in the war so it can be studied and, hopefully, copied by the Allies. Using the relatively available cartridge will ease the job both for Germans and the Allies, later making the copies in thousands before the VE day. Small change vs. Italian cartridge being introduction of the spitzer round.
 
Briefly at the end of WW2 the British were considering the 7.92mm Mauser as used in the BESA as a standard new round. The Pedersen takes a tapered 51mm case to give the same performance as the 43mm .280. An improved 6.5 Carcano will almost do the trick pretty well off the shelf. off the shelf. It is telling that pre WW2 the Italians were only interested in short ranges for their 6.5 and improved the round by a lighter fatter bullet for those short ranges with the 8x59mm Breda for the machine guns which had the longer range role. The ,276/.280 were at the crossover to work in both types.

What might have happened with a POD where Churchill didn't roll over and play dead for his masters?
 

Deleted member 1487

I'm not sure whether it was suggested before, but how about this: Germans make the FG-42 in 6.5mm Italian? Should've been more controlable in automatic fire, and it is early enough in the war so it can be studied and, hopefully, copied by the Allies. Using the relatively available cartridge will ease the job both for Germans and the Allies, later making the copies in thousands before the VE day. Small change vs. Italian cartridge being introduction of the spitzer round.
I don't think the Italians had any to spare before they dropped out of the war; they got caught trying to caliber convert right before the war and then had to switch back to 6.5. The thing is that the Germans overran a bunch of nations that used 6.5mm rounds, so it shouldn't have been that hard to adopt one of them for the FG42, but I guess the Luftwaffe was highly concerned about ammo compatibility for their paratroopers, so didn't want a different caliber or even specially modified 7.92mm cartridge potentially disrupting resupply.

That said I think the 1943 7.92 SmE Lang bullet actually came close to the Italian 6.5 in recoil impulse due to using a bullet nearly the same weight, but much higher ballistic form factor, and having a reduced propellant load due to the long all steel bullet sitting more deeply in the cartridge case.
http://www.cruffler.com/Features/JUL-01/trivia-July01.html

AFAIK the FG-42 never used that bullet, instead sticking to the SmK bullet (flat base bullet with a steel core).

Alternatively the Luftwaffe apparently also used an aluminum cored bullet (leichtes Spitzgeschoss) that was MUCH lighter, something like 85 grains (the standard lead cored bullet, schweres Spitzgeschoss was 198 grains for reference) and a muzzle velocity of 3035fps, which was approaching 5.56 NATO muzzle velocity. This 7.92 lS bullet was apparently for ground based machine guns to use for anti-aircraft work. Not sure if it had a lower propellant load, which would impact the muzzle fireball the FG-42 was infamous for.
http://mauser98k.internetdsl.pl/ammoinfen.html
lS - leichtes Spitzgeschoss - anti-aircraft
  • missile weight - 5,5 g
  • muzzle velocity - 925 m/s

Using that round in the FG42 would mean you could make it a lighter weapon overall and extremely controllable, while the ammo itself would be much lighter to carry.
 
Come to think of it, knowing the US style they probably would do a Kahn factory and mill out the weapons like the expensive lighter alloy first version of the FG42 (with V2 handgrip and bipod placement):
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They had good reason the make many changes on the second model of FG42. For example, the wooden buttstock prevents your face from freezing to your gun during Russian winters. FG42-2 switched to pressed steel to simplify production and avoid using scarce steel alloys.
I have fired a modern, German-made replica of a First Model FG42 and loved it! It recoils less than an FN FAL and is lighter to carry.
Recoil is so light that if a NATO nation adopted an updated FG42-2, they would not bother with 5.56mm ammo.

Master Corporal Rob Warner, CD + graduate of Bundeswehr Luftlande Lufttransport Schule
 

Deleted member 1487

They had good reason the make many changes on the second model of FG42. For example, the wooden buttstock prevents your face from freezing to your gun during Russian winters. FG42-2 switched to pressed steel to simplify production and avoid using scarce steel alloys.
I have fired a modern, German-made replica of a First Model FG42 and loved it! It recoils less than an FN FAL and is lighter to carry.
Recoil is so light that if a NATO nation adopted an updated FG42-2, they would not bother with 5.56mm ammo.

Master Corporal Rob Warner, CD + graduate of Bundeswehr Luftlande Lufttransport Schule
Extremely cool. Was it in full auto? Do you think the reason it was so light recoiling was the muzzle brake?

Yes the 2nd version definitely made a number of critical improvements (though the original version apparently was supposed to be made of stamped steel, but was changed to get the weight down). I wonder if the US did adopt the FG-42 adapted to the 7.62 NATO or a version of it (say the CETME 7.62 bullet with a plastic tip filling and a lead base to keep weight down and aid in the tumbling effect while maintaining the aerodynamic, long shape) what sorts of improvements they'd make to it, like with to the muzzle brake or replacing the wood with fiber glass like in the M16. If they did adopt some of the features of the AR-10 they could make it significantly lighter with an aluminium receiver. Though that may make it too light given the propellant load. If they say keep the German version, that is the aluminium cored round, with the new 51mm cartridge case, they could very well have their light recoilling, pretty hard hitting 'intermediate' round.

But I don't see the FG-42 preventing the M16 necessarily, but if it gets light enough it is possible that we could see a version of it adapted to the 5.56 round. Or even better IMHO a 6mm variant like the 6x45mm SAW
 
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What's about that Spanish really long bullet CETME developed that was on Forgotten Weapons. Excluding the political issues with it.
 

Deleted member 1487

What's about that Spanish really long bullet CETME developed that was on Forgotten Weapons. Excluding the political issues with it.
It was absolutely viable technically speaking and was in fact tested by the US against the various other light rifles of the day (FN FAL, M14 prototype, and EM-2 prototype) and supposedly proved superior. Politics was the primary issue there AFAIK.
http://municion.org/7_92x40/7_62x40.htm
This was the 7.62 version to conform to the existing US demands in terms of caliber. It would have been an interesting choice. Not available in time for the Korean War though, where it probably would have been the most useful, but it would have been for Vietnam. Basically it would been heavier than an AKM in weight by a bit, but significantly easier to control in automatic and much longer ranged. It should have have similar penetration abilities too, but it would have been much heavier than the M16 and heavier recoiling than the 5.56mm NATO round. Plus each round would have been significantly heavier, meaning you could carry fewer of them. However it would have been as long ranged as the 7.62 NATO round, if not better, much lighter per round, same length overall, but probably significantly worse penetration. A belt fed version would have been very interesting, but it would have significant issues trying to replace the 7.62 NATO in an MMG role due to it's low sectional density resulting in lower energy especially at longer ranges (despite staying supersonic out to 1000m). Plus it apparently would have had significantly more drop and drift at longer ranges, which would impact accuracy noticeably. Not necessarily the biggest issue with a belt fed automatic weapon though.
https://www.thefirearmblog.com/blog...al-intermediate-calibers-022-7-92x40mm-cetme/

Now the CETME concept with a iron-aluminum alloy core to raise the weight a bit and applied to say a 5.56mm bullet would also be highly interesting.
 
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