Japanese small arms

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Senior Master Sergeant
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Jun 27, 2007
A few questions.
Did the Arisaka type 99 rifle use different ammunition than the Type 92 hmg?
Did the Japanese have access to German or Italian small arms during the axis time frame?
And if so why didn't they try and copy it?
How did the type 92 fare in real world combat? Very obsolete by 1945 but still fired rounds.
Was the type 14 Nambu and type 94 Nambu really that bad?
Did the rivalry between the navy and army make Japanese small arms production harder?
How damaging was the change from 6.5mm to 7.7mm cartridge?
 
The Type 99 shell for the Arisaka type 99 rifle was less powerful but the size 7.7×58mm was same as the Type 92 shell for the Type 92 hmg but early version of the Type 92 shell was semi-rimmed and not recommended for the Arisaka type 99 rifle. That was improved to the rimless type after February 1940 for the perfect compatibility.

German and Italian small arms were either too good or too bad for Japanese.
Sorry but I don't know appropriate answers well for the rest of your questions.
 
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Did the Japanese have access to German or Italian small arms during the axis time frame?
And if so why didn't they try and copy it?
There was no reason to copy an Italian weapons except perhaps the submachine guns. The Japanese weapons may not have been much better but they certainly were no worse.
The Mauser 98 had no real advantage over the Japanese rifles. The Japanese issued very few sub-machine guns, doctrine? lack of decent pistol round of their own? lack of manufacturing capacity?

How did the type 92 fare in real world combat? Very obsolete by 1945 but still fired rounds.
Old school machine guns usually did fairly well. They were well made and rugged. in short battles (days or weeks) major problems are not likely to show up. Everybody's heavy machine guns came with a "kit" of a few tools and few replacement parts for items subject to breakage. Like spare firing pins and extractors. Cyclic rate of fire so beloved by article writers actually had very little to do with actual "firepower". Most heavy machine guns could go through a small truck load of ammo about an hour regardless of cycle rate. 200rpm for 60 minutes is 12,000 rounds. The actual limits were barrel cooling, jams, parts breakage (2-3 broken parts per 10,000 rounds is actually pretty good) and trying to stuff new rounds into old belts, feed strips, magazines, etc. Even bunkers/pillboxes were unlikely to have 10,000 rounds of MG ammo ready to load into the guns.

Was the type 14 Nambu and type 94 Nambu really that bad?
In a word, yes. But since pistols cause something like well, well under 1% of combat casualties it isn't that big a deal in the general scheme of things. The vast majority of type 14 Nambu pistols were actually quite well made, the main failings being perhaps too well made (trait shared by German Luger) with small tolerances making them sensitive to dirt, grit, etc. and the low powered cartridge.
The Type 94 is really strange, a six shot automatic??

Did the rivalry between the navy and army make Japanese small arms production harder?
As far as aircraft weapons go yes. As far as infantry weapons go it doesn't seem to be that big a deal. The Navy pretty much adopted Army weapons for their marines rather than design different weapons.
 
I have always believed that if the Japanese had equipped their troops with the relatively simple SMG and Panzerfaust it would have made a huge difference in their combat strength
 
The Type 38 was already a Mauser so no need to copy there.
The Army had plenty of self loading rifle designs in the 30s but shelved them as war in China was starting.

The Japanese did have smgs but simply not in quantity. The Type 100 using the same 8mm Nambu round the pistols used. Not powerful but alright. Many writers critical of the 8mm Nambu easily forget that 7.65mm pistols were very common in German army.

How the Japanese missed the SMG is telling especially in jungle war.
The Japanese did use a variation of the panzerfaust which involves man running at tank with explosive charge.

The Japanese could have done well looking at a new pistol (p38 or ppk), SMG (MP40) and the MG34 or MG42. Type 96/99 lmg was good and the type 38 and 99 rifles were as good as any other bolt action. Type 11 lmg was brilliant idea but not in practice and the Type 92 was old school Hotchkiss. Odd for British or American writers to critique the Type 92 because they used the same design in WW1. Type 92 was durable but not close to a MG42.

Japanese pistols were flawed and although I agree the pistol is not a battlefield weapon at least make it good. The Type 94 should have been rejected out of hand. The Type 14 dunno maybe the bad mouthing it gets is due to lack of Proper 8mm Nambu and poor handloads.

Read somewhere that the Navy had a different 7.7mm round than the Army which is crazy.
My favourite Japanese rifle is the Type I Carcano which must be a sign of the times when you get the Italians to build your rifles. The Navy had to buy from Italy because all the rifles were for the Army. It fired the 6.5 Japanese using a standard stripper clip and the not the Mannlicher clips but kept the Carcano bolt.
 
My biggest issue with Japanese small arms isn't about the poor design. Their rifles were workable. their MGs were lacking but good enough. Pistols were poor but it didn't really matter. SMGs were non existent. but these weren't the big issue. The problem with Japanese small arms was in the methods of production, using the old world machining and requiring much precision engineering to build. Okay if you have the industrial base to absorb that effort but the Japanese were lacking in that department. They needed to adapt their weapons for mass productions, using stampings and forgings where possible, minimising reliance on precision engineering wherever they could. this was the outstandingf achievement of the Germans for some of their weapons (but not their rifles), like the MG42 and the MP-40. Cheap as chips to build meant more available and less expense and less raw materials demands. Russians went at it slightly differently, very simple designs really, lacking in any design flair, but easy to make, resistant to dirt, PPSH for example used worn out barrels froom the Moisin nagant rifles cut in half basically.
 
The 8mm Nambu was a substandard military round. There is no two ways about it.
The 7.63 Mauser/7.62 Tokarev used a slightly lighter bullet (85-86 grains vs 102 grains) at a much higher velocity around 1400fps (depending on exact load) vs around 950fps. They had around 150% more kinetic energy. The 9mm Parabellum used heavier bullets (115-125 grains) at higher velocities, 1200-1300fps (some submachine gun ammo was higher velocity) so again power was was in another category. Velocity for the sub-machine gun rounds is important for penetration and for trajectory. The Italians used the 9mm Parabellum for their sub-machine guns rather than the dimensionally identical 9mm Glisenti used in their pistols. If you expect the submachine gun to be effective at 100-200yds the 8mm Nambu is going to found wanting.
The German use of the 7.65 X 17mm Browning round was in some ways due to inability to make enough 9mm service pistols and in part due to officers being armed even in off duty situations. Also for aircrew and tank crew. It was also the most widely use dpistol round in Europe before and after WW I. The 7.65mm Browning was better than no pistol but hardly a true service pistol round either. A 71 grain bullet at around 1000 fps is hardly in the same league as the big 3 (.45ACP, 9mm Parabellum and 7.62 Tokarev)

"Odd for British or American writers to critique the Type 92 because they used the same design in WW1. Type 92 was durable but not close to a MG42."

what could be overlooked in 1914-18 when the machine gun was about 30 years old could not be overlooked as easy when the machinegun was 50-60 years old. The Type 92 can be traced back to the 1897 Hotchkiss. A good gun in it's time but it's time had come and gone by WW II. The MG 42 was a good gun but perhaps not so good for the Japanese. It's high cycle rate was in part due to the requirement to be used as an AA gun. It was of little practical help in ground fire. Keeping them feed could present a problem and the way they worked in tripod mounts was a frequent replacement of the barrel. Several barrels in rotation to keep from burning out the rifling.

"Read somewhere that the Navy had a different 7.7mm round than the Army which is crazy."
Actually this may be a legacy round. The Japanese 7.7mm aircraft machineguns were variants of the British Vickers and some 30s aircraft used Lewis guns as flexible guns. These guns used a copy of the British .303 round.
 
. They needed to adapt their weapons for mass productions, using stampings and forgings where possible, minimising reliance on precision engineering wherever they could. this was the outstandingf achievement of the Germans for some of their weapons (but not their rifles), like the MG42 and the MP-40. Cheap as chips to build meant more available and less expense and less raw materials demands. Russians went at it slightly differently, very simple designs really, lacking in any design flair, but easy to make, resistant to dirt, PPSH for example used worn out barrels froom the Moisin nagant rifles cut in half basically.

Good stampings are actually not that easy to make. Just because you can make headlight reflectors doesn't mean you can make machinegun receivers. Submachine guns are easy because blow-back actions are not complicated and stresses are low. Making belt feed machineguns out of stampings is a lot harder. There were several machineguns during the 30s (and early 40s) that tended to fail in rather spectacular fashions after only a few thousand rounds (an improvement over the Chauchat but still....)
The stories about the PPSH using worn out Nagant barrels sounds good and may even have been done on occasion but there seem to be a few problems.
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The flange area is bigger in diameter than the diameter of the rifle barrel once you get a hands width or two from the the chamber. Maybe the Russians used a two piece barrel on the Submachine guns? Skinny barrel held in a sleeve?
Or perhaps since rifle barrel blanks can come from the rifling machines in lengths over 30" (well over) and full diameter for the length of the blank you can cut up barrel blanks intended for Nagants into convenient lengths and turn the outsides to what ever dimensions are needed. Drilling, reaming and rifling of cut rifling barrels (as different form hammer forged barrels) or even button rifled barrels was done on rods of steel usually over an inch in diameter to avoid distortion and scraping due the stresses of machining.
 
I like the Chauchat!
The Chauchat is an interesting design for its day. Flawed but I do rather like it. Considering the Chauchat is the problem of 2016 thinking and not 1914. is the Chauchat that bad? The Lebel 8mm or the American .30? Wasn't there so can't say!
The Japanese didn't have the industrial base or the raw materials to be a superpower and got caught out. So they lost the moment the Arizona blew up. Hubris and belief in your own superior skills don't get very far.
The 8mm Nambu is a weaker round but a 8mm machine gun is better than no machine gun. Most sub machine gun contacts are face to face especially in the jungle so long range is not issue.
The Japanese did borrow heavily from Europe in small arms and then didn't. It surprises me that someone didn't look in 1940 didn't say ' wow a lot of our weapons are now behind the curve' but probably too late by then.
 
I like the Chauchat!
The Chauchat is an interesting design for its day. Flawed but I do rather like it. Considering the Chauchat is the problem of 2016 thinking and not 1914. is the Chauchat that bad? The Lebel 8mm or the American .30? Wasn't there so can't say!
The only thing going for the Chauchat was that it was cheap. In fact too cheap. A little more money spent on manufacturing and quality control might have paid big dividends. A good example of the gun might very well fire thousands of rounds with only a few minor parts breakages, a few bad examples started cracking welds under 400 rounds. These may have been the 30-06 model which stressed the gun more due to the higher power. The long recoil system (barrel moved the full length of the cartridge) not only lead to the slow rate of fire (not that big a problem) but to the gun vibrating or shaking to a considerable degree, combined with a ,shall we say, less than ideal fit of the barrel in it's casing this resulted in rather gross inaccuracy limiting the useful range of the weapon. The long recoil system also means that the rear of barrel pretty well fills the ejection port if the gun jams with the barrel in the rearward position making clearing certain jams nearly impossible although adding to gunners curse word vocabulary. The system also means a higher possibility of jams due to dented or bent barrel casings, not likely but still... There was just too much wrong with the basic design and it was compounded by shoddy manufacturing. Alternatives were available but were more expensive.
The Americans got stuck with this thing due to a feud between the inventor of the Lewis gun, colonel Issac Newton Lewis and the US Chief of Ordnance General William Crozier. The Marines going to France had already been issued Lewis guns but had them taken away and replaced by Chauchats by order of Crozier. The Lewis gun started manufacture in Belgium in 1913 (after Lewis moved there upon resigning from the US Army due to the feud) and was in Production in England in 1914 and in the US by Savage in 1916.


The 8mm Nambu is a weaker round but a 8mm machine gun is better than no machine gun. Most sub machine gun contacts are face to face especially in the jungle so long range is not issue.
If you are going to build a few thousand sub-machine guns for an army numbering in the hundreds of thousands (or 6 million)then chamber them for the crap pistol round you already have. If you are going to build them by the tens of thousands or hundreds of thousands then chamber them something that is going to work and build the ammo factory to suit. Building weapons to a lowest common denominator standard got a lot more armies in trouble than you might think.

The Japanese did borrow heavily from Europe in small arms and then didn't. It surprises me that someone didn't look in 1940 didn't say ' wow a lot of our weapons are now behind the curve' but probably too late by then.[/QUOTE]
 
The Chauchat is a case of being interesting engineering to me.
I think the design is fascinating. If you remember the P13 Enfield this was designed for the Veldt. Where I doubt any gun was designed with mud in mind.
I know that full auto will make it jam and the magazine was open to all sorts of muck but it was quite something for the times.

I disagree on the Type 100 SMG. The gun was made in so few numbers as to be almost worthless but in my view it could have been effective.
It may have been a case of Hobsons choice as it was the only game in town as trying to either copy design a new gun with new ammunition would have been impossible say in 42 onwards.
SMG seems to have passed the Japanese by like a warm summers day. And that's a good thing as that would have made them more combat effective in certain environments. Good for Britain!
 
"Read somewhere that the Navy had a different 7.7mm round than the Army which is crazy."
Actually this may be a legacy round. The Japanese 7.7mm aircraft machineguns were variants of the British Vickers and some 30s aircraft used Lewis guns as flexible guns. These guns used a copy of the British .303 round.[/QUOTE]

I read somewhere that IJN fighters with mixed 7.7mm/20mm armament used a "detuned" 7.7 round whose trajectory matched the low-velocity 20mm cannon for aiming purposes. Pilots have written that they steered the 7.7 tracers onto the target, then squeezed the firing button to the second detent to fire the tracerless cannons.
 
The British had a need for smgs so they copied the German Mp28 and called it the Lanchester and made the Stem.
So smgs not that difficult. I would assume it wasn't something they were interested in. The Lanchester was able to fix bayonets which must have been Japanese in origin!
Of course even making a copy of a tried and tested weapon is difficult. If you don't have the industrial resources.
 
one should not forget the origins SMGs. They were designed as a close in trench warfare weapon and more or less that remained their main area of employment until as a concept they were superseded by the assault rifle, which combined the functions of SMG and conventional rifles. I mention this because the Japanese during WWI and most of the interwar fighting done by the Japanese didn't entail a whole lot of static warfare. most of their fighting didn't entail a whole lot of static close in fighting. In china where this kind of fighting was at least approached, the battles were still mostly manoeuvre battles and battles fought with ranged weapons. A battle fought at hand to hand ranges with a horde like the stick wielding chinese army isn't going to end well. MGs set up in fixed positions were best for this, on the attack, regimental cannons, backs up by divisional artillery, could usually be relied upon to break up major attacks or punch holes in the defenders line. SMGs just weren't that necessary for the IJA in their pre-war experience
 
The war in China would be a very bad yardstick to judge future war. Oddly the Japanese learned that 6.5mm isn't powerful enough and changed to 7.7mm
The Battles of Khalkhyn Gol were better judges of Japanese capacity and they learnt don't go to war with USSR go to war with USA instead.
In a nutshell the Japanese got themselves in a war they couldn't win.
Their best hope would have been to invade the Soviet East as part of Barbarossa. Something which the Japanese army had been advocating for years.
The defeat at Khalkhyn Gol meant no Siberian invasion and gave the navy thier project of Pacific conquest the green light instead. Gotta invade somebody.
The SMG may not work in a set piece battle but on small tropical islands or jungle warfare it works a treat.
I spoke about the Enfield P13 in another thread and it is indicative here. The P13 was ideally suited to long range sniping against an enemy who also used long range sniping as thier primary form of warfare. P13 thinking would have made the SMG useless.
 
The Japanese had been doing a slow change from the 6.5mm to the 7.7mm round. It started right after WW I adoption of the of 7.7mm (aka .303) as an aircraft machine gun round. From there it spread to the heavy tripod ground machine guns and a few intermediary Aircraft guns. The British .303 not being a good design for automatic weapons (to was done but the round is far from ideal) the taper was reduced and the rim made smaller. The Heavy ground machine guns tended to be used a long ranges and bigger, more powerful round was thought to be an advantage.
The size of rims tends to go along with quality of brass and quality/size of extractors and violence of primary extraction. As brass quality gets better smaller rims can be used. However small extractors can pull though rims and guns lacking primary extraction can get really bad at leaving cases stuck in the chamber. Bolt action rifles use the camming effect of lifting the bolt handle to help break the cartridge fee of the chamber walls ( their is also a lot more time for the case to cool and shrink) before pulling the length of the case from the chamber. Bolt action rifles being rather gentle in extraction (unless operator is beating on the bolt handle with a rock).
If the Japanese were interested in penetration of battle field obstacles by their mgs and rifles the adoption of possibly the lowest powered Sub machine gun in the world up until that time makes no sense. Even the French Mas 38 was roughly 20% more powerful.
The Japanese round had roughly 1/2 the penetration in wood of the 9mm Parabellum.
And by 1942 it should have been obvious that the world was shifting to stamped sheet metal submachineguns. The receiver of a submachine gun being little more that a frame work to hold a bolt, spring, trigger mechanism and feed device. Bolt is held closed by the weight (inertia) of the bolt and the tension on the spring. Unlike a machinegun receiver where the locking mechanism usually fastens the the bolt and receiver together for a short period of time and the receiver has to withstand the firing stresses. MG 42 was an exception as the bolt locked to a barrel extension. Machining the barrel extensions and bolt heads was not an easy task.
mg42bolt.jpg

mg42_04.jpg

As the barrel recoiled a short distance cams in the receiver body forced the rollers towards the center of the bolt and out of engagement with locking recesses in the barrel extension. Barrel stopped and bolt continued rearward.
In comparison Sten gun bolts even got to the point of machining the firing pin on the face of the bolt.
MkIII07.jpg

Gun fired as the cartridge came to a stop in the chamber.
 
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The closest western round to the 8mm Nambu is the .380 ACP and considering the age of the 380 it does seem it's use as a SMG round was very slim.
But the Type 100 was about so the Japanese must have thought it had some merit. I can't find any details on a 9mm pistol in Japanese service so would have assume there wasn't and so building a SMG out of the mass produced 8mm round made sense and however weak the round was it was better than a 7mm Nambu!

The .380 was perfectly ok in ww2 and sub 9mm pistols were very common in German use. PPKs and all that
Of course today the tacticool crowd wouldnt touch a ,380 round and consider even the 9mm to be barest minimum. I don't know how reliable the Type 100 is but I still think if it had widely available it would have been far more effective than an Arisaka in close quarter battle.
 
Try looking up the actual ballistics.
BTW the 8mm Nambu replaced a 9mm Revolver in Japanese service.
1f3209924eeb4c36daefcf70d2aeb948.jpg

The Japanese had the majority of their officers purchasing their personnel pistol(firearm) from their own private funds. Very few of the pistols were actually government issue although the ammo was.
Using substandard ammo/cartridges is never a really good idea. Better than nothing is faint praise indeed when with a little more foresight a better cartridge/weapon could easily have been obtained. And in the late 30s/early 40s not a lot of foresight was needed to figure out that a cartridge using a bigger, heavier bullet at higher velocities than the 8mm Nambu would be an advantage in a submachine gun. The 9mm Parabellum was only 36 years old in 1938 so it's not like asking for cartridges from the future. As far as supply goes, The Japanese, as noted above, where NOT handing out pistols to cooks, truck drivers, artillery crewmen and the like some some other armies. These troops got type 38 carbines with 487mm barrel( 19.7in) so while the 8mm Nambu cartridge was government issue the scale of issue was small compared to some western nations. If you are really going to issue submachine guns in quantity then the need for ammo is in the tens of millions of rounds if not hundreds of millions of rounds for a 6.5 million man army.
Such numbers would totally swamp existing production facilities so any "savings" in using exiting tooling would soon disappear. Drawing dies do wear out and have to be replaced on occasion anyway so the original 8mm tooling wouldn't last that long either.
 

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