[Kaylee]

seems like every other day I hear someone say that a 6.xmm is an incredible "magic number" for rifle rounds... was that not what the Japanese were using before they moved up to a 7.something--mm? Or were there other issues? Why the change?

-K

[Hkmp5sd]

The Japanese initially used the Arisaka Type 38 6.5mm in both rifle and carbine forms. During their fighting in China during the 1930s, they decided they needed a more powerful cartridge. Their arsenal already had a 7.7mm semi-rimmed cartridge being used in the Type 92 heavy machinegun. They developed a rimless version of that cartridge and adopted it and the Type 99 rifle in 1939.

[Mike Irwin]

A bullet redesign would have been another good option.

The Japanese found, as did the Italians and other users of similar 6.5mm rounds, that their wounding potential was pretty limited.

The bullets used in these rounds were very long, were relatively heavy, and as a result had pretty high sectional densities. That, in turn, meant that the would penetrate like crazy, but wouldn't flip or go unstable and cause nasty wounds.

This penetration capability is one of the major reasons why Karamajo Bell used the 6.5x54 Mannlicher Schonauer on elephants.

When the Italians tried to switch to the 7.35mm round, they did a very good job of redesigning the bullet so that it went unstable very quickly after hitting tissue, which heightened its wounding potential quite a bit.

The Japanese did something similar with the 7.7 (for all intents and purposes it was a rimless .303 British), and it did show marked improvement in wounding capabilities.

The Italians at least tried to change their caliber in the middle 1930s, but weren't very successful because the depression of the 1930s hit them pretty hard. They did issue some 7.35s, but ended up pulling the rifles and issuing 6.5s for the duration of the war, and even rebarreled some 7.35s back to 6.5.

The Japanese attempted to switch rifle rounds in 1939, which given their expanding military base, was pretty much a guaranteed failure. Still, the type 99 Arisaka was used throughout the war.

[JohnKSa]

When it comes to WWII Japanese small arms, there is no need to ask why.

The answer is always: "The Japanese were clueless when it came to small arms in WWII." ;)

[Chipperman]

When you see some of the crappy small arms and machine guns they were using, it's a wonder they did so well with them.

[Jim K]

Well, the Japanese rifles were not all that crappy, nor were their MGs. Wartime propaganda pictured Japanese arms as junk, their soldiers as cowards who could not shoot due to their slanted eyes, and their 6.5mm cartridge as no better than a .22. A lot of Americans found out the hard way that those were lies. I wonder if one example of "clueless" is the simplest rifle bolt ever devised, with only 6 parts compared to 12 or so for the Model 1903.

As to the power of the 6.5, it depends on which 6.5 we are talking about. The small case military rounds, Italian, Greek, Japanese, are not too effective and were usually chosen for light recoil and economy. But the 6.5x55 is a whole nother ball game, as are cartridges like the .257 Roberts, the 6.5 Remington Magnum and the .25-'06.

The Japanese actually used three 7.7 rounds. The semi-rimmed ground MG round and rimless rifle round have been mentioned by Mike, but they also used a rimmed 7.7 that was a renamed .303 British and was used in the Navy's license-built Lewis guns.

HTH

Jim

[JohnKSa]

The fact that their rifles were very simple and could be used to kill people doesn't impress me. There are companies that prove daily that a reasonable measure of function is possible without decent quality. The Japanese economy of design likely had much more to do with their extreme metal shortage than design genius.

I can't think of any other country in WWII who armed their troops more poorly than the Japanese.

FWIW, I'm not sure how the reputation of Japanese troops became a topic discussion on this thread, but it wasn't something I meant to be construed from anything I posted.

[Hkmp5sd]

The Japanese weapons prior to 1943 were not poorly designed or "crappy." The Type 38 had a slightly modified Mauser action. Only after 1943 did the weapons quality start to drop due to their lack of materials and manufacturing capabilities.

I don't remember which one off-hand, but one of the books I have mentions after the war, tests were performed on the type of material and strength of the action of the various WWII bolt action rifles. The results indicated the Type 38 action was stronger than the Springfield, Enfield and Mauser actions.

[Mike Irwin]

Oh I beg to differ on the subject of machine guns! BIG TIME differ!

The Japanese had some unfreaking believably Rube Goldberg MGs, with seriously assnine operational systems!

The Japanese never could copy a workable design without mucking with it in such a way that it was made less reliable, less effective, and overall less desirable as a battlefield weapon.

Despite years of experience to the contrary, they never quite grasped the importance of primary extraction until almost the very last design (I don't have my references in front of me, and can't remember the different model numbers).

Virtually every Japanese MG up to the one in 7.7mm (the type 96?) had to have the cartridge cases oiled before chambering as a guard against the action ripping the case head off during extraction.

The Japanese approached this in a number of ways (and all of them sucked!) -- oil the cartridges as they are loaded into the ready magazines, have oiled pads in the action of the gun that wipe the round as it is fed into the chamber, or worst of all, actually have a mechanism that sprayed oil INTO the chamber during the loading cycle.

To try to get around this, the Japanese tried fluting the chambers on some of the guns. Nice try. The case would swell tightly into the flutes, and the action would rip the case head off, making it doubly difficult to clear the jam. So, back to the oiling.

Then we had the 6.5mm LMG that had a unique hopper feed mechanism on the side. The gunner would drop 5-round stripper clips into it, and the rounds would be stripped into the action. All in all, very interesting. No loaded magazines to cart around, meaning that the gunner and assistant could carry a lot of loaded strippers without the extra weight of the magazines.

And, theoretically, the gunner can cadge strippers from riflemen to feed the gun if necessary. Theoretically, because the designers put the gun together, and it wouldn't work with the standard 6.5mm rifle ammo. It was too powerful. So instead of redesigning the gun, the Japanese simply put a less powerful variant of the ammo into service! Theoretical advantage negated.

Then we have the odd design feature of many Japanese light and even medium machine guns being capable of having a bayonet fitted. Interesting, but questionably useful.

Those are just a few of the worst elements of the machine guns that the Japanese fielded during their expansionist period, but it's by no means a complete list.

Other Japanese arms ranged from very good design, such as the Arisaka series of rifles (the late war rifles were badly made, there's no doubt about that) to mediocre, including some variants of the self-same rifles and the two submachine guns that they actually fielded in limited numbers, to absolutely abysmal in the visage of the Type 94 pistol.