Explain why the Japanese dumped 6.5 mm for 7.7 mm full power.

>>34323178
The common thought at the time was that intermediate and medium sized rifle calibers did not have the range required for battle. At the time they didnt know most engagements took place at under a few hundred yards

>>34323221
Did no one ask the soldiers "About how far away was the last burger/jap/jerry you shot at?"

>>34323265
>expecting the average soldier to actually know anything about guns or ballistics
Where do you think fuddlore originates?

Bolt action rifles and machineguns vs automatic rifles and lmgs.

>>34323178
>And now our military wants 6.5?

The military does not want 6.5.

This aready happened after the invasion of Iraq in the 2000s. Millions of dollars were funneled into developing and testing replacement cartridges for the "anemic" 5.56. The results were the 6.8SPC, 6.5 Grendel, and a few others. They weren't adopted and they never will be.

This is make-work for small arms manufacturers to R&D new rounds that are functionally identical to existing cartridges. They will get tons of money to do so. The military will then buy a million rounds of each for testing, further enriching those companies. By that time the US will have left Afghanistan and there will be no reason to even feign interest in the results. The project will be dropped, and the resultant cartridges will have some commercial success as the cutting edge tactical caliber of the decade.

Wait 10 years, repeat.

The 6.5 was not designed to disrupt inside of the body like the .303 and 5.56 are. To that end, wounds from the caliber were quite benign unless they hit bone or vital organs. Bigger calibers are more effective absent advanced bullet design.

We should've gone with .280 British because it was the best caliber being considered at the time when recoil, weight of arms and ammunition, and tactics are considered. Shot for shot it is inferior to 7.62 NATO but the only combatants where each shot is critical are snipers. Snipers typically aren't issued standard infantry rifles for obvious reasons.

The 6.5 seems to make the most sense these days in part due to advanced bullet design but also because it is somewhat of a golden point between recoil, trajectory, weight, terminal effect, and barrel life.

>>34323553
>The 6.5 was not designed to disrupt inside of the body like the .303 and 5.56 are.
None of those calibers were designed for that purpose and all of them are perfectly effective with the right projectile.

>>34323178
They were concerned about stahpan powah! Although there are doubts about the validity of that claim as it can be argued 6.5 was more than sufficient

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>>34323582
Idk about the .303 but 5.56 was most certainly designed to derive its lethality by fragmenting like a motherfucker.

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>>34323178
There was also the .276 Pedersen. That got pushed aside because of logistics, though. The Garand's biggest design flaw actually comes from scaling it up to .30-06 Springfield. The "dog leg" in the op rod had to be added to accommodate the larger barrel diameter at the chamber.

>>34323656
Vietnam era 5.56 didnt even fragment. They have now designed projectiles to fragment but it wasnt the original intention.

The same for .303 brit. The original loading was a favorite for shooting elephants through the skull but mk vii bounced off skulls because the tip of the jacket was hollow, causing it to yaw.

>>34323494
They do want it. Good luck with your anti military industrial complex term paper though.

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>>34323494

>>34323494
Learn your history kid. The SAW was originally planned for 6mm. But the Army wanted 1 cartridge at the squad level. They couldn't abandon 5.56 because it was already bitterly accepted as the NATO standard. However everyone knows that an intermediate cartridge in the 6mm range is superior given that bullets have to be shot on earth with earth gravity and earth air density. The FAL and L85 were also originally designed for something in the 6mm range.

>>34323841
>M193 doesn't fragment
But that's fucking wrong retard

>>34323960
talk is cheap, until the army actually adopts one of these calibres, who cares.

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>>34323841
Of course it fucking did fragment.

>>34323948
They want the capability, but will balk at the cost and the compromises that will have to be made in order to achieve it. Duelling with your opposition at long range is a zero sum game, and giving up mobility and logistic advantages to be better at it is inane.

>>34323960
I saw the same articles floating around in 2005 talking about the SPC. They may as well be copypasta.

>>34324051
All the memes

You can get a lot out of the .223 with a high BC bullet. Giving the average infantryman extreme long range capabilities will depend on a lot more than just a new cartridge. You're looking at a long barreled, relatively heavy rifle with optics appropriate to the task. This is like a COD player coming on to /k/ and asking "lol y don't we just make all soldiers snipers."

>>34326531
>high BC bullet
You realize we are talking about a 6mm SAW? The idea was one cartridge at the squad level. Every soldier may not be able to be a DM, but BC of a 6mm will always beat a 5.56mm.

>>34323629

Compared to .308, .280 was less accurate and didn't have tracers that worked reliably. The conclusion of the first report was that there should've been better quality ammunition sent for testing the next time around but the British never got around to it. IF the British asked the Swedes for help they could've amounted to something.

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>>34323494
>By that time the US will have left Afghanistan

K then...

>>34323178
6.5mm in a bolt action was probably fine terminal-performance-wise but with pew rack pew you might want more penetration so larger cartridges make more sense

>>34323288

if you haven't squared someone in your sights and gunned them down enough times to know how it's supposed to go... then you, my friend... know jack fucking SHIT about guns.]

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>>34323841
>tfw he says XM193 didn't fragment from a 20" barrel

>>34324051
>The FAL and L85 were also originally designed for something in the 6mm range.

Learn your history kid.

>>34328142

You realize this thread isn't about the 6mm SAW, but about alternatives to the M4?

You have to strike a compromise betweem performance, mobility and logistics. The 5.56 when loaded well is a good compromise.

>>34328423

Maybe you think the whole military should be restructured to better fight illiterate goat herders in a country only deemed important enough to keep ~8k troops in, but it seems pretty retarded to me.

>>34324106
>>34324228
>>34328461
I was mistaken about m193 specifically but the point remains that .223 was not designed specifically with the intention of maximum destruction.

>>34326531
You mean a negative sum game?

>>34330745
>specifically with the intention of maximum destruction
Except that it was.

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>>34330745

>.223 was not designed specifically with the intention of maximum destruction.

This better not be this "designed to wound, not kill" nonsense.

>>34323178
>>34323178
>Explain why the Japanese dumped 6.5 mm for 7.7 mm full power.

Machine Guns, doctrine changes.

>But /k/ says NATO should have gone for .280 British
/k/ is also retarded. But they're right. It's a good thing they didn't, but they're right.

Infantry combat is predicated on volume of fire. 7.62x51mm NATO does not lend itself to creating volumes of fire as high as .280 would have. But .280 was worse in every way as an infantry cartridge than 5.56x45mm. if .280 was adopted it's unlikely 5.56 would have been adopted.

>And now our military wants 6.5?
Kind of.
>What gives?
It's probably a testbed thing. The army find itself unable to reliably penetrate modern body armor at the upper end of protection levels with single shots of 5.56x45mm. 6.5 offers a solution to this while realistically keeping the ammunition count and volume of fire high, but also offers a tested solution.

Nothing will come of it in all likelihood, unless polymer or caseless or PCTA ammunition is cleared for use.

Nevermind that, how long do you think it'll take before they start making sense and realise that 9.3x62 is ideal? I'm not even gonna mention .375 H&H or .458 Lott, because by the time they realise that those are all you'd ever need for anything, we'll be so far into the future that they'll be throwing money on some laser rifles instead.

>>34331224
Except it wasnt. The only requirement on terminal ballistics for .223 during development was that it had to have wounding ability equal to .30 carbine

>>34323553
>The 6.5 was not designed to disrupt inside of the body like the .303 and 5.56 are.

/2012/05/02/the-6-5x-50-arisaka-imperial-japans-intermediate-cartridge/

In reality, the wound was likely to be not so miniature. The wounding effects of the Type 38’s bullet were described in some detail by a U.S. Army medical report:
The .256 bullet, especially one made with a gliding metal ( an alloy of copper and zinc ) jacket, when it hits the target had an explosive effect which tended to separate, leaving the entire jacket in the wound while the bullet went on through. Small globules of lead scattered through the wound and embedded themselves elsewhere in the flesh. This condition was the result of the fact that the rear section of the walls of the bullet jacket, which was filled with a lead core, were thinner than the forward walls . The sudden stoppage of the high velocity bullet when it hit an object produced a tendency to burst the rear walls causing an ” explosion.” The lead core, which had a greater specific gravity, penetrated, leaving behind the relatively lighter jacket from which it had been discharged… The unusually large exit wound openings often found with this caliber of bullet were due to the natural instability of the bullet and the possibility of its being fired from inferior weapons. Similarly, there were elliptic entry wounds, a result of the ” keyholing” effect of bullets hitting with their sides.

>>34323178
The Japanese shifted because of a few reasons:
>Bullet technology of the time provided poor wounding ability with 6.5
When facing Chinese forces, armed with 8x57 Mauser, they noticed that the larger bullets would more easily incapacitate their soldiers while their 6.5 bullet would often leave the enemy capable of fighting (even if in a limited fashion)
>Tracers/AP/API/Incendiary rounds
Bullet tech at the time did not allow for satisfactory Tracers or Armor piercing rounds in anything smaller than a 30 caliber.

Simply, it comes down to bullet technology at the time. Even non-signatory countries would play by the Hague Convention (see US and Japan), so hollow and soft point ammo were off limits. Tumbling, frangible, armor piercing and tracer rounds were just not advanced or cheap enough to warrant equipping an army with a 6.5 round unless you had a small military force. Another country to look at would be Italy who also at the time tried changing from a 6.5 (.268 dia) to 7.35 (.300 dia).

As to why now the trend is toward mid diameter bullets (6.5-7mm) is the technology now exists to create cheap bullets that can most military roles. We have been using the current 5.56x45 for 50 years with only slight changes to the bullet and some of the upper brass is starting to wonder if there is a better option.

>>34332037
And yet they crushed that requirement with a round that performed incredibly well, and is the baseline for bullet effectiveness to this day.

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>>34328449
>valor projecting on 4chan...

>>34332037

>The only requirement on terminal ballistics for .223 during development was that it had to have wounding ability equal to .30 carbine

And that it had to be able to penetrate a steel helmet at 500 yards.

>>34323178

Well, when you're still using bolt-action rifles, you really want dat stoppin' powah because you can't do follow-up shots as quick as with an auto-loader. With an assault rifle it isn't a big deal if somebody doesn't do down immediately because it is pretty simple to just pop a few more rounds onto an enemy that stubbornly refuses to die.

>>34323178
>But /k/ says NATO should have gone for .280 British,

No it doesn't.

>>34324051
>Learn your history kid
>The FAL and L85 were also originally designed for something in the 6mm range.
Fucking ironic.

>>34323841
>Vietnam era 5.56 didnt even fragment
Yes it did, you dipshit, in fact, M193 generally fragments substantially better than M855.
You hit a gook in the hip with an M16A1 loaded with M193 and he will never walk again, assuming he lives he might have his leg amputated.

>>34323178
>/k/ says NATO should have gone for .280 British
Only anglophile fags do.

>>34328967
>5.56 when loaded well is a good compromise.
What load?

The Army has long been dissatisfied with 5.56. M193 was too light. M855 was too long/heavy but they needed a bullet with an 800m trace for the SAW. We have consistently had problems with 5.56 in Somalia and Afghanistan. M855A1 is an attempt to boost the power of 5.56. It is loaded too hot.

No. The Army has done everything they can with the 5.56. It needs something with better range and power. Even going back to 7.62 has been looked at as an interim solution.

Right now, I would argue 6.5 Grendel is in the ballpark.

>>34337746
>M193 was too light
It certainly is nothing amazing by today's standards but it was never a bad performer.
They could learn something from the Mk.262 Mod 1, not issue that exact load, but the Open Tipped Match bullet I think has vast potential.

>Even going back to 7.62 has been looked at as an interim solution.
By absolute mouth breathers.

From what I understand the shift to the 7.7mm was for the islands in the Pacific.
Japanese forces on mainland Asia still mostly used the Type 38 and 44 with the 6.5 round, but those on the island were given the Type 99 with the 7.7 round because it could go through more foliage and not lose its power.
interesting because a few decades later, the Americans in Vietnam shifted from a heavier cartridge to a lighter one. A conflict where penetrating dense foliage was also required.

>>34338257
>A conflict where penetrating dense foliage was also required.
I think they just weighed all the advantages of a true assault rifle with a lightweight cartridge against foliage and barrier penetration (which of course a battle rifle does well), and decided the tradeoff was worth it, and maybe that the M60 could pick up the slack in that department.

>>34324051
>They couldn't abandon 5.56 because it was already bitterly accepted as the NATO standard.
Was it? I thought the development and trials of 6mm SAW were done in the 70s and the adoption of 5.56 as the standard NATO round occurred in the early 80s.
>The FAL and L85 were also originally designed for something in the 6mm range.
Wasn't it 4.85x49mm that the Brits were experimenting with? That's actually smaller than 5.56.