View Full Version : 7.7x58 jap ammo

November 3, 2012, 12:33 AM
Ok I have two cases here both stamped 7.7x58 jap graf, which I think is hornady, and the other is stamped 7.7x58 jap PPU which is priv. Now my question is why does the graf look way diff than the ppu? the neck and shoulder are completely diff... the brass length is the same but if you looked at them side by side you would say they look like completely diff rounds/caliber any suggestions why this is? They both shoot fine but I notice the PPU theres a little blow back from the round due ot the shorter neck and sligther shoulder. Again this isnt somebody necking down 30-06 or what ever , they both from factory stamped 7.7x58 jap but they sure dont look the same.

November 3, 2012, 01:16 AM
pictures might help out a little with explanation, of both rounds side by side and the boxes.

November 3, 2012, 01:31 AM
here is a phote attached

November 3, 2012, 01:46 AM
here are the boxes it came out of, one box head stamped 7.7x58 jap graf and another 7.7x58 jap PPU. again same exact box brand new from store but brass size is different

November 3, 2012, 01:51 AM
see the diff between the two cases, again brand new out of the box I dont understand the diff?

November 3, 2012, 01:53 AM
They look like they were fired in a .30-06 chamber and one fireformed more than the other.

Do you have a couple of unfired cartridges to compare? I imagine they'll look the same.

Has your Arisaka been rechambered?

November 3, 2012, 01:59 AM
sport, i dont know i bought it a local gun shop. they couldn't have been fired formed from 30-06 brand new out of the box.

November 3, 2012, 02:03 AM
I dont have any rds left with the shorter neck, but here are some brand new rds to compare again these all came out of same box brand new, I have only fired these once.

But I did compare the shorter neck case to an 30-06 case and the shoulders identical, the neck just has been trimmed down, im baffled, may the manf ran out of 7.7 brass and just necked down a 30-06 case. remember these were brand new rds

November 3, 2012, 02:12 AM
they are not NIB.
hornady has their own head stamp. also if I understand you correctly you only purchased the brass and the boxes state a bullet weight, only found in preloaded ammo. what you bought was somebodies used brass which they reboxed and sold to to your local gun store. I will agree with the assessment that one was mistakenly fired from a 30-06 and the casing fire formed out to the chamber dimensions while the other appears to have been fired from the proper chamber.

EDIT: I just re-read the original post. you say that the PPU/PRVI blows back?

stop firing at once and take it to a gun smith to verify chamber.
I will almost bet that your rifle was bored out to 30-06.

November 3, 2012, 02:20 AM
so your saying they reloaded somebodies used brass, and boxed in a hornady box, because I bought the box of ammo, not brass....

also for **** and giggles, I put an empty 30-06 brass and wahla!!! it fit and bolt closed, you both were right. This is a plus because as you can see a box of that jap ammo is not cheap and I have loads of 30-06ammo and components to reload it with.

November 3, 2012, 03:04 AM
No, that's not what I was saying. The ammunition in question is proper 7.7x58 Arisaka. Your gun has been rechambered for .30-06.

Will .30-06 fit in the magazine? If it does the gun has had some proper work done to it. If only the chamber is modified you have a bolt action single shot.

I'd have the headspacing checked to be sure everything's okay for that round. The 'smith should also stamp the appropriate chambering information on the barrel while he's at it.

7.7x58 is a shorter round than '06. Because of the long bullet jump there wasn't a whole lot of pressure needed to get the bullet out of the case. After that, there wasn't a whole lot of pressure difference between the inside and outside of the case since you didn't get a good seal at the neck. One brand of case was harder that the other and didn't stretch as much.

November 3, 2012, 03:13 AM
yes 30-06 does fit in the magazine, bolt cycles cleanly I put a live round and cycle bolt no issues, but the bullet diameter for 30-06 is .308 and for 7.7 its .311 wont this make a difference?

im also going to gun smith tomorrow to pick up another firearm, i will have him check it out and make sure it is chambered for 30-06 or for 7.7x58.

November 3, 2012, 04:53 AM
You'll probably want to slug the bore. Mine is 0.313" but shoots Hornady 174gr .312 bullets well.

If your gun is a rechambered 7.7 it will probably shoot .308 bullets okay (if 3-4" at 100 yards is acceptable). If it was mine I'd load .312 bullets in .30-06 cases.

If you load .312 bullets MAKE SURE the neck area of the chamber is not pinching the loaded cartridge by painting a loaded round with magic marker and inspecting it for drag marks and such after chambering it a couple of times. Arisakas are tough, but not that tough.

Mike Irwin
November 3, 2012, 07:33 AM
One other thing you need to know...

The Arisaka round is slightly larger at the base, so unless the barrel was set back, the chamber is going to be oversized, meaning your .30-06 brass will swell at the base. Not a good combination for long-term case life.

James K
November 3, 2012, 05:55 PM
I don't know who shot John, but I do know that that 7.7 case was fired in a .30-'06 chamber. I have a bunch like it that I fired in a M1903 Springfield to check out stories by WWII vets that they could fire Japanese ammo in the American rifle.*

As to the cases being "brand new", the labels clearly show they came from a reloading shop, so I think they got something mixed up someplace. Maybe they put a returned box back on the shelf without checking, I don't know. But there is no way a factory produced those short neck cases. Period.


*I did just that. No sign of any excess pressure, no sign of any significant case swelling, and even the clips work just fine!


November 3, 2012, 10:01 PM
I don't see anything wrong with the ammo from the Hornady boxes. Hornady probably doesn't make their own 7.7x58 brass so different lots having different headstamps really doesn't surprise me. The boxes do, however, look pretty worn for being new off the shelf.


In any case it appears all the fire forming was done in the OP's rifle. 7.7x58 has a shorter neck than '06 but the really short necked fired case is a result of the 7.7 being fired in a .30-06 (or other) chamber. We really don't know what the OP's rifle was rechambered to, only that a .30-06 will fit....

'06 is a good bet though since it was a common conversion for a bring-back rifle with no local ammunition availablility.

The case on the left fireformed more because it was softer. The one on the right didn't fireform much at all. Or maybe the one on the left just had a better neck seal, who knows.

Mike Irwin
November 3, 2012, 10:55 PM
" I have a bunch like it that I fired in a M1903 Springfield to check out stories by WWII vets that they could fire Japanese ammo in the American rifle.* "

The stories I have always heard is that the Japanese could fire .30-06 ammo in their Arisakas.

Load of kitchen crockery.

James K
November 4, 2012, 12:44 AM
Nope, it won't work the other way. I had heard both stories years ago, and thought the same as you. Then I heard the "7.7 in Springfield" story from a source who is almost always accurate and decided to try it. I admit to being a bit surprised at the result. Not only did the 7.7 (Norma) rounds load from the Japanese clip but it fired fine and I could not tell it from the .30-'06. I fired 20 shots and got a 100 yard group of about 6 inches. (I checked with the scope, I didn't pick up the target.) With my aging eyes and iron sights, and wrong ammo, I thought that was pretty good.

Two points of interest. The "oversize bullet" (.311 vs .308) did not blow up the rifle, cause the bolt to come back into my head, or wipe out the county. There was, in fact, no sign of any significant pressure increase; the primers looked quite normal.

The supposed case swelling didn't happen either, nor did it with reworked .30-'06 fired in a Japanese rifle. The base dimension for the .30-'06 is .470 +/- a thousandth or so. The base dimension of the 7.7 Japanese is .471 again +/-. In practical terms, they are the same. So blown cases, bulging brass, go the same route as other myths.

There is probably some confusion from the fact that the Japanese used three different 7.7mm cartridges.

1. The rimless 7.7x58, which we are discussing. It was used in the Type 99 rifle and the Type 92 light machine gun.

2. The 7.7 semi-rimmed was used in the Type 99 heavy MG, a Hotchkiss type; the feed strips are around at gun shows occasionally. Some folks buy them thinking to use the ammo in their rifles; won't work.

3. The thrid 7.7 round is rimmed; it is simply the .303 British made for use in the Japanese Navy's licensed copies of the Lewis gun.


Mike Irwin
November 4, 2012, 07:15 AM
I could swear I have something around here, and I'll be darned if I can remember what it is or where it is, that indicates that the nominal base diameter of 7.7 military rifle ammo to be closer to .480 than .470...

I know the .311 bullet isn't an issue. if anything, that will raise pressure a few thousand PSI, if any at all, from the nominal working pressure of the cartridge, and IIRC the nominal working pressure for the 7.7 is 54,000 PSI, while for the .30-06 its closer to 65,000 psi, so there's a lot of inherent leeway.

Oh, by the way, I've seen several Arisakas over the years that would chamber the 7.7 semi-rimmed ammo out of the feed strips. Don't ask me why or how.

November 4, 2012, 09:44 PM
I rarely agree with Mike, but the base difference is quite wide between an '06 and a 7.7, depending on who's brass you use. Winchester is one of the smallest cases made. Grab a handful of different brands and mike the bases on unfired rounds. If you would take a small case (Such as Winchester) and use it in an Arisaka with a max chamber, it could rupture if loaded hot enough. I recently sold an Arisaka at an auction that was re-worked to 30-06 by the U.S. Military during the Korean War. It had all the stampings and was the weird phosphate green. The difference is that military brass is large and quite heavy compared to commercial brass. Pretty much the rupturing starts as the loads increase. I once fired a factory .300 Savage in a 7.62x54R chamber (Long story) and the brass looked normal. The factory loads are usually quite light. On the other hand, there are many people that were not so lucky with unsupported cases in the wrong chamber. The original poster was not too clear, but I think he said both cases were headstamped 7.7 JAP. The shorter one was just loaded lighter and did not expand.

James K
November 4, 2012, 10:02 PM
No, the base runs just what I said; in reloading 7.7 Jap, the .30-'06/.308/8mm Mauser shell holder is used. But I will clarify my non-interchangeable statement a bit. The 7.7 semi-rimmed will fit into the 7.7mm rimless chamber but the rim won't fit into the bolt face of the Type 99 rifle. So it won't feed from the magazine, and if it is dropped into the chamber the bolt cannot be closed on it so it can't be fired.

The 7.7 rimless rifle cartridge apparently will feed from the strips, but I have been told that the gun will be unreliable because the extractor won't always grab the smaller rim. I cannot test this condition, as I have no Type 99 HMG handy, so I am going by what I have read.


November 4, 2012, 10:53 PM
I've used a lot of reformed '06 cases from M2 ball in my 7.7 and can say that it does swell a bit above the web. I generally use them twice and then put them in the recycle bucket.

I've heard people swear they've run surplus '06 in their Arisakas but I have a hard time believing it. I tried and couldn't force an empty '06 case into mine. Well, I suppose I could if I was willing to take a hammer to the bolt...

The slot in my Type 99 is a little too wide for '03 clips, but they'll work if you don't get in a hurry. Arisaka clips (I wish I had some) might be too wide for loading a '03 rifle.

James K
November 5, 2012, 06:47 PM
The clips are not identical, one difference being the position of the lugs, and the fit in the other rifle is not perfect, but will work.

Of course, firing .30-'06 in a 7.7x58 chamber is impossible for the reason you mention. It would take a big hammer.

FWIW, there is only one Japanese rifle clip; the 7.7 and 6.5 use the same clip.


November 5, 2012, 07:24 PM
When is the last time someone here reloaded original Japanese 7.7 brass? No argument there.

Mike Irwin
November 5, 2012, 10:11 PM
Unfortunately I don't have an example of a Japanese military 7.7 rifle round in my collection.

"The 7.7 rimless rifle cartridge apparently will feed from the strips, but I have been told that the gun will be unreliable because the extractor won't always grab the smaller rim. I cannot test this condition, as I have no Type 99 HMG handy, so I am going by what I have read."

The Type 99 was a magazine fed light/medium machine gun. The Type 92 was based on the Hotchkiss pattern and used the 30-round clips.

I have, around here somewhere, a 30-round clip for the Type 92.

November 6, 2012, 12:37 AM
The Type 99 was a magazine fed light/medium machine gun.

My Type 99 is a bolt action rifle with an internal magazine that holds 5 rounds and can be loaded from a stripper clip or one at a time from the top.

If Japan had two Type 99's it would explain why I'm having trouble understanding the business about it feeding from a clip.

Mike Irwin
November 6, 2012, 07:35 AM

Sorry, I was addressing Jim's comment regarding Japanese automatic weapons.

The Type 99 is a Japanese Arisaka rifle.

The Type 99 is also a Japanese magazine fed light machine gun.

The Type 99 is also a Japanese 81mm mortar.

The Type 99 is also a Japanese hand grenade (the "Kiska" model, where it was first encountered)

And finally, the Type 99 is also a Japanese 20mm cannon used primarily as an aircraft weapon.

There may well have been other Type 99s, as well.

November 6, 2012, 07:46 AM
That must have been a good year for them. :)

James K
November 6, 2012, 09:53 PM
Right on the machineguns. My bad, I had the Type 92 (Hotchkiss type HMG), and the Type 99 ("Jap Bren"), reversed. Anyway the 7.7 semi-rimmed was made for the Hotchkiss type and that is what is in those feed strips.* The latter took the same rimless round as the Type 99 rifle.

Sport45, the confusion comes because the Japanese used the date of adoption, as the U.S. did until the 1930's. Every firearm adopted in 1939 (2599 in the old Japanese calendar) was a "Type 99". As Mike says, a Japanese saying "Type 99" would have to say "Type 99" what. We have the same problem with, for example, Model 1917, which could be a rifle, one of two different revolvers, or a Browning machinegun.

*Edited to add that I just looked at the box and even I, with almost no Japanese, can read "Type 92".


Mike Irwin
November 7, 2012, 07:26 AM
It's also the same as saying M 1 in US parlance.

For example...

M1 Garand

M1 Carbine

M1 Helmet

M1 Combat Car/M1A2 Light Tank

M1 81mm Mortar

M1 Submachine Gun (simplified Thompson variant, quickly replaced by the even simpler M2)

And the list goes on and on...

44 AMP
November 8, 2012, 01:03 AM
M1 Submachine Gun (simplified Thompson variant, quickly replaced by the even simpler M2)

ah...that would be the M1A1, IIRC, Mike....and then the much simpler M3 and M3A1 Greasegun....

Military designations are such fun....
When someone says M4, are they talking a bout a 5.56mm carbine, or a Sherman tank?:D

And is a P-38 a 9mm pistol, or a fighter plane? OR a GI can opener?
Yes, depending on context

and there is at least one other Jap type 99 that I know of, the Aichi Type 99 dive bomber (known as the "Val" to US forces)

I'm sure there's more, we just have to find them...type 99 chopsticks? M1 Bootlace?

November 8, 2012, 01:47 AM
Definitely get the chamber of that rifle identified. It is not 7.7x58mm Jap.

If you're not familiar with the process of taking a chamber cast (or don't have the proper measuring tools), take it to a competent gunsmith. They'll take a cast, ID the chamber, and can stamp the barrel for the appropriate cartridge (required by law).

Take it back to the shop you bought it from, and tell them you're getting hit in the face by debris, every time you shoot it.
If they don't offer to take the chamber cast for free, push the issue. If they still refuse, you have a very shady dealer that should not be trusted.

November 8, 2012, 04:11 AM
Take it back to the shop you bought it from, and tell them you're getting hit in the face by debris, every time you shoot it.
If they don't offer to take the chamber cast for free, push the issue. If they still refuse, you have a very shady dealer that should not be trusted.

Or drop a .30-06 in the chamber to show that you know it is definately not a 7.7x58 and only know that it is at least as large as a .30-06. Go on to tell him that it is not a .30-06 since the bore is at least 7.7mm.

Mike Irwin
November 8, 2012, 07:34 AM
"ah...that would be the M1A1"

Yes, the A1, my mistake.

The M2 was a developmental dead end.

James K
November 8, 2012, 12:07 PM
Just to out-nitpick, the P-38 was a fighter plane, the "P" standing for "Pursuit", the old name for a fighter. The P.38 was a German WWII pistol. The period was correct because the "P" was an abbreviation for Pistole. The postwar version was just the P38 (no period). I haven't checked on the can opener.


44 AMP
November 9, 2012, 02:06 AM
oh yes, James, very correct.

And FWIW, my "expert" called me tonight and told me there were four (4) "type 99" aircraft in service with the WWII Japanese Army, and a couple others with the Navy. Type 99 was a very popular designation, and bascially could refer to anythingy designed or adopted in 1940.

Mike Irwin
November 9, 2012, 09:14 AM
'Type 99 was a very popular designation, and bascially could refer to anythingy designed or adopted in 1940.'

No, it was 1939, as Jim noted, as 1939 in the Gregorian calendar was 2599 in the Japanese imperial calendar.

And, it wasn't anything designed in a particular year, it was the year that it entered military service.

Additional examples, the Type 0 fighter, or Japanese Zero, which entered service in 1940. It got a hell of a lot worse later in the war, though, when another system was adopted on top of that system...

The old Japanese system of nomenclature used to use the then current emperor's name and a numeral designation equal to his years on the throne.

For example, the Arisaka 6.5mm rifle was the Meiji (emperor) Type 38 (years of his reign).

James K
November 9, 2012, 02:14 PM
And of course, the fighter should really have been called the "00" but they dropped one "0" and called it the Zero (Japanese designation). That designation caught on, and Americans almost always called it the "Zero", even though the official Allied code name was the "Zeke".) The actual Japanese designation was A6Mx, with the x being a number indicating a change. Minor changes were indicated by an additional "model" number. Major changes to the basic type were designated by a letter. The Zeros used at Pearl Harbor were designated as A6M2 Model 21.


F. Guffey
November 9, 2012, 03:23 PM
A reloader/shooter/collector purchased a 7.7 Japanese that had been modified. He ask a question about cases, being concerned about the price of cases he expressed an interest in forming cases. After everyone told him everything they knew about Japanese rifles I got involved, helping him was not something that could be done on a forum so I contacted him and gave him my contact information. I offered to form cases for his 7.7 for free, he agreed but was reluctant. I formed 80 cases, I kept 2 from each box in case there was a question.
I used new and once fired cases, I used 4 different head stamps. I formed the cases with a 308 Winchester forming die, I formed the cases long from the head of the case to the shoulder then full length sized the cases with A Herters 7.7 Japanese full length sizer die.

When finishing the full length sizing process I screwed the die down to shell holder on the first 20 cases, then I backed the die off the shell holder .005” for the next 20, I backed the die off .009” to size the the next 20 cases, for the last 20 I backed the die off the shell holder .014”, I mailed the cases to him. He sent the results to me, he said the first set chambered so he loaded them, he said the next set chambered with slight resistance to bolt closing so he loaded them, he then said the third set would not allow the bolt to close so he full length sized them and he loaded that set, same for the fourth set. he full length sized them and then loaded them also, the last 2 sets required trimming.

He lives just west of Ft. Worth, TX., he had a couple more questions so I made arrangements for him to meet me at the Dallas Market Hall gun show, by the time he got to the show he had fired all the cases at least 3 times each. He had some gun parts he needed checked out so he bought them with him, he was given an opinion and introduced to resource people.

He had a question about the forming process, he wanted to know how I knew his chamber was go-gage length as in the first set chambered with no resistance to bolt closing, I informed him I did not have a clue what condition the chamber was in, I explained to him I formed cases that matched the length of a a minimum length chamber, a go-gage length chamber, a no go-gage length chamber and a field reject chamber, all that was required of him was to let me know which set chambered. It did not take him anytime at all to catch on. Again, if I had one forming die it would be the 308 Winchester, if I had two forming dies the second one would still be in the 308 W family like the 7mm08 or the 243 Winchester etc..

F. Guffey

44 AMP
November 9, 2012, 03:30 PM
my bad, wrote 40 when I meant 39.

Another interesting tidbit, for equipment dating 1940, the Japanese Army used "type 100" while the Navy used "type 0". probably to reduce the confusion, although it seems that reducing confusion was not something the Japanese miliary excelled in, evidenced by 3 (or more?) different types of 7.7mm ammo, not interchangable. And other things....

Supply officer had to have been one of the most aggrivating and frustrating positions in the Japanese military....

November 9, 2012, 06:23 PM
Just out of general curiosity, anybody know what the "Type I" 6.5 rifle was designated as by the Japanese? I often thought that was something we hung on it.

James K
November 9, 2012, 09:20 PM
Hi, Gunplummer, if you find out, let me know. I have been digging around for a long time and can't find the answer. I am not even sure the Japanese didn't call it that.

Hi, 44AMP, I think the confusion was probably more for modern collectors than for the Japanese. The 7.7 rimless was issued only in clips that fit the Type 99 rifle. The 7.7 semi-rimmed was issued only in feed strips for the Type 92 HMG, and the 7.7 rimmed (.303 British) was issued only to the Navy for their Lewis guns. So there would be few if any chances for confusion.

I think there would have been greater chance for a mixup with the two types of rifle ammo, but they reportedly made sure a given regiment or division had only one caliber rifle.


Mike Irwin
November 10, 2012, 09:32 AM
Regarding 0 vs 00 designation, the Japanese made a conscious decision to start at 0 and use single digits until they got to 10.

That designation system was supplemented by the Ki designation used for various types of aircraft.

The entire Japanese procurement and designation system was a boondoggle in large part because the Army and Navy were so competitive and often very much in conflict with each other.

James K
November 10, 2012, 09:59 PM
Reportedly, the services agreed to split Zero production and the Army insisted on its half, even though they were not using the aircraft and didn't need them, while the Navy was desperate for more carrier fighters.

The army usually got their way because an army general was prime minster; the good of the country had nothing to do with it.

Almost sounds like the Pentagon today, doesn't it?


Mike Irwin
November 10, 2012, 11:40 PM
Zero production was never split. The Army and Navy had their own design and production channels, and rarely shared anything the intraservice rivalry was that strong.

The Type 1 Ki-43 "Oscar," the IJA's primary fighter during much of the war, bore a very strong resemblance to the Zero fighter and often caused quite a bit of confusion among Allied pilots.

Later in the war, as the IJN's carrier forces were whittled down and the Navy's role became progressively more marginalized by the simple fact that there were fewer and fewer places for them to place aircraft as the Allies island hopped across the pacific, many of the remaining Zeros were assigned to defend the home islands and to serve as Kamikazis.

The Army was primarily in charge of home island defense, so it would have been in charge of whatever Zeros were left, but they were always flown by Naval aviators, not Army aviators.

November 20, 2012, 01:35 AM
I will never buy a gun from that shop again, i thought i was getting a steal on an iver johnson m1 carbine that was in great shape for 400.00 shot 100 rds thru it and it wouldnt cycle also the firing pin was also broke because there were no strikes, no big deal easy fix, still was having cycling issues the flipping gas piston was broken in half everybody i talk to couldnt believe it. So i had to fix firing pin and gas piston for carbine to work.

Now that i find out that the arisaka shoots 30-06 instead of 7.7 really ****** me off. There not doing my transfers any more either.

November 20, 2012, 12:42 PM
amen to that, something like failing to verify that a gun has been rechambered is forgiveable IMO since most gun shops just list what is on the barrel anyway but an M1 carbine that is completely trashed and being sold as operational draws the line for me, 2 strikes and you're out in my book.

Old 454
November 21, 2012, 10:15 AM
The p38 can opener was placed in cases of "C"-rats or rations, it was also known as a "John Wayne" at least that was told to me by the marines that were on the LST troop carrier I was on in the 70's