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Discussion Starter · #1 ·
Raladan asked about this with respect to Nagoya, while looking through my 'spare' bbl/receivers I noted the following:

Nagoya-
assembly numbers on bbl and receiver, usually an arabic number over 3 other arabic numbers, present on examples of no series, 2,3,4, and 5th series number 50,961 which had a 3 over 130 ass. number. Series 6,7,8,11 none.

Tokyo- here is were it gets curious to me-
20th- one with number on receiver only, none on bbl, two other 20ths without any ass. numbers
21st- one with, again on receiver only, one without any, 23- none, 25-none

Toyo Kogyo- also interesting.
30 through 33rd series, have three digit numbers on the bbl only, numbers do not match the serial number; 35 none.

Tokyo Juki Kogyo- no assembly numbers. Two rifles examined, both with chrome bores.

So how did the Japanese assemble the rifles to achieve headspace?
A-Assemble, headspace, remove barrel for chroming?
Using a stamped assembly number on bbl and receiver; or perhaps in the case of TK,
a list of bbl numbers keyed to receiver numbers?
B-Headspace before assembly to a 'standard' receiver?
C-A combination of both or neither???

Nagoya through the mid 5th series would represent system A. But what did they do in the 6th and 7th, most of which still have chromed bores?

Fredh,
any ideas or recollections? Edokko, another area for reading in the archives!
 

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hi 03man
thanks for the info , this helps alot, for nagoya assembly numbers, and t99 sniper production . to be honest never gave the other arsenals a look at ... so far ALL t99 snipers observed have the assembly numbers and you reported a mid 5th series rifle ,(50961/3 over 130 ass.) sniper production began late in the 5th series , in the 90,000 serial range ? ok ,does any one have a 5th series ,serial number inbetween 50961 and 99,999 that they can share info with, in regards to a assmbly number ?
thanks
 

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03man, my work bench is covered with another project now, and I don't have room to start taking rifles apart. I do suspect that a higher degree of interchangeability was realized in production by the time T99 production began. The only reason I can think of to put assy numbers on parts is that a lot of hand fitting is required because tolerances cannot be controlled to the degree required. It's my understanding each arsenal had production under its own control, so process planning would set up production flow based on machine availability and capability. That would explain why some arsenals used assy numbers on the bbl/receiver; others didn't. It's interesting assy numbers came back strong with start-up of Garand production. That rifle must have been a bear to manufacture, plus by '45 machine tool capability was a major problem. Anyway, the barrels were probably rough reamed prior to assy and finish reamed after assy to receiver. Barrels could be chrome plated before or after assy. I can't think of a reason either why a barrel would have to be removed to machine the receiver for a scope base. I guess I've answered your question; I seem to be dancing around a lot.
 

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Discussion Starter · #4 ·
Raladan,
How many 99 snipers have you observed? Did they cover the full range of serial numbers by Nagoya? How about Kokura 99s?

I have one of each, but am a little lazy to take a complete rifle apart, If you list serial numbers already observed, mine may be irrevelant.

Fred,
Interesting comments, and it is clear that the different mfgs. had different systems or capabilities.

On the garand, the headspace spec is likely much tighter than for the 99, IIRC, only some 3 or 6 thousands from go to fail? I'm guessing the 99 has an acceptable range of at least 10 thousands and more likely 15; a much easier target to hit. Thoughts?
 

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On the garand, the headspace spec is likely much tighter than for the 99, IIRC, only some 3 or 6 thousands from go to fail? I'm guessing the 99 has an acceptable range of at least 10 thousands and more likely 15; a much easier target to hit. Thoughts?
When I was a kid shooting the Japanese rifles, I always checked headspace before shooting, always hoping to find one with about .005-.008. Not! It was not uncommon to find T99s with .013, a number that sticks out in my memory. I still fired them. The fredh method was typical of a kid, holding down and away, turned ninety degrees clockwise, and firing. Of course, I used the poor man's method of headspacing, dad's Gilette reds trimmed to fit and stacked 'til non closure. It worked for me and didn't blow one up that way.
 

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Discussion Starter · #6 · (Edited)
You may have seen this picture of a 6.5x 50 round fired in a 6.5x 57 chamber by yours truly. Best I can figure it amounts to about 0.250 of 'headspace'. I would never have known it had I not ejected the shell where I could see it.

Don't try this at home!

Now where is that dang picture? Couldn't get one to show, now I have two, go figure. 6.5x50 on left, fired cartridge center, 6.5x57 on right.
 

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hi 03man,
the rifles observed did cover the spectrum of most of the production ,i have some info and shared info from vicasoto, so i'll let him give you the details . but as i recall serials from nagoya as low as 100 to 6400 have been observed . like you said a lot of t99 snipers still need to be looked at ,so if your willing to help out and send vicasoto your info that would be great ....... as for the question of machineing the reciever to accsept the scope base, i would think that a 'jig' was manufactured to ensure that every reciever was ....1st -machined identical and results of the machineing same .... 2nd -for speed of manufactureing , 3rd - labor , it doesnt take a master machinest to machine the reciever with the use of a jig and simple instructions , its far easier to work with a 7 inch reciever than a 32 inch unit . 4th rejection rates minamised .... these are only my opinons but they are sound mfgr princables. they produced 10,000 t99 snipers in a very short time . so the arsenal new what they were doing .....
thanks
 

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Discussion Starter · #8 · (Edited)
Just remember that there may also assembly numbers on the receiver cut out and the matching scope mount base, IIRC. At least there are on the T 97s; you can see the assembly number on the 97 below, all the screws and pins are in slightly different alignment from rifle to rifle, necessitating an assembly number.

Anyone with a 99 with the base removed? I suspect they are the same with respect to screw/pin alignment.

Actually it would be simpler, IMO, to mill the receiver with barrel attached( IF working with completed rifles); rather than to mark, dis-assemble, mill, and then re-assemble them. It matters not if the barrel extends out from the milling vise. At least that is my experience. Perhaps even more circumstantial evidence for selecting receivers before assembly with barrels???

Just another thought, it seems that the double Na final inspection supports mfg. from finished rifles; but, what if, it signifies something else entirely, like final sighting with the dedicated scope? Seems to me some 'final' marking with scope attached and sighting confirmed could be expected? But then maybe not.

Way more questions than answers.

Victor need to pose any questions in a new thread and ask for input from everyone, JMHO. I have been gratified by the response when a question was put to the members here.
 

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hi 03man,
dont forget that if were talking completed rifles modified to snipers , how did you reblue the reciever after the milling process was complete , yes the new milling that the reciever got was blued ,not left in the white and reassembled . so did the barrel get 2 coats of blueing ???... or was the barrel taken off at some point, in the work to complete the transition ......
 

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Discussion Starter · #10 ·
Yep, 2 dips in the tank would not alter the final apprearance, IMO.

So the receivers and bases should have an assembly number on the 99s also, unless they are "in the white" under the base?

Have you seen a 99 with the base removed? is there an ass. number there?

Where is Victor, is his computer kaput?
 

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Hello 03man :

Only Nagoya 97s have a barrel to receiver assembly number, it consists of arabic numbers, a one digit over three others, there is a separate base to receiver assembly number stamped on the backside of the base and middle of the machined area, therefore this is only visible if the base is disassembled. This base assembly number consists of a Kanji or kana over a three digit arabic number.
I have three examples based on loose parts in my study kit :
1) Nagoya 97 # 10426, barrel to receiver 1 over 371, base to receiver unreadable Kanji over 686 .
2) Nagoya 97 # 10754, barrel to receiver 1 over 642, base has not been removed.
3) Nagoya 2.5X loose base, assembly number " ni " over 444 . Note that Kanji "ni" stands for two.
Nagoya 99 snipers have barrel to receiver assembly numbers consisting of 3 digits. Three early rifles also have an external base to receiver assembly number, so far all are under serial number 200. I took apart my rifles and have some additional data from fellow collectors :
1) Nagoya 99 # 151, barrel to receiver 117, base to receiver 122 .
2) I also have data that base to receiver on Nagoya # 167 is 98, and # 172 is 203.
3) Nagoya 99 # 311, barrel to receiver 254 .
4) Nagoya 99 # 3138, barrel to receiver 530 .
5) Nagoya 99 # 4600, barrel to receiver 769 .
6) Nagoya 99 # 7110, barrel to receiver 697 .
From the pile of loose actions I noticed the following receivers had assembly numbers :
a) Nagoya 4th series # 70740, assembly number 213 .
b) Nagoya-Tokyo 27th series # 17521, assembly number 530 .
c) Kokura 20th series # 20027, assembly number hiragana 386 .
Have a box of loose receivers but haven't located them yet.
Vicasoto
 

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hi 03man
well what we can determine from the limited data so far is
#1- nagoya stopped useing assembly numbers in regular production some time in the mid to late 5th series .
#2- nagoya t99 snipers are made in the late 5th and 6th series ( no one has reported any assembly numbers from regular 6th series production yet )
#3-nagoya as it appears reintroduced assembly numbers with t99 sniper production.
#4- the assembly numbers are used to keep the barrel and reciever together and as reported in very early t99 sniper production the base to reciever number was to keep them together as well .
#5- assembly numbers in t99 sniper production ,there for ,must be a part of the building process .
assembly numbers in t99 snipers ,were used in order to assure if the rifles were taken apart for any reason they could be reassembled .
just my to cents
thanks
 
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