"Factory" Chamberings For Japanese Type 99

[TCLouis]

I have a fully sporterized Type 99 that I had bought many years ago and after determining that the chamber was nothing I had brass for set aside in a dark corner.

Well the bug hit me to make that gun a shooter (cast of course) and so I have been dropping brass of every description in her to see what I have.

Standard type 99 barrel profile and shape
Witness marks line up
Dies not seem to be chrome lined
Face of bolt machined perfectly smooth, but standard case head diameter.
Swallows a 7.62X39
Will not chamber a 7.7X58 by a good bit.

Ramp front and Williams rear peep.
Work is all first class including the blue.

Any ideas what chambering some crusty old gunsmith might have created?

[mwells72774]

Could be a tight chamber? Have a argy 1909 Mauser with a very tight bore in our gun shop.

[corbinace]

Time to break out the Cerrosafe for a chamber cast.

If you have not done it before, be not afraid. Even I can do it.

I enjoy the process.

[TCLouis]

corbinace
When I get the gumption, I can't find my CerroSafe.
When I find the Cerro Safe I can't work up the gumption.
Guess I will make locating the Cerrosafe a priority.

AND

Having a specific place to store it like everything else.

[bruce drake]

Many gunsmiths back in the day shortly after WWII, they would take a turn off the threads and rechamber the Type 99s as 300 Savage. You might have one of them since it has been sporterized. If the sporterizing happened after we adopted the 7.62x51/308Win chambering for our M14/M60s, some T99s were rechambered for 308 Winchester. Either one will have better accuracy with .311/312 bullets but as a economy deer rifle, standard 308win or 300 Savage cartridges will still hit a deer at 100 yards.

[Multigunner]

If .311 or larger J-Word bullets are hard to find I've found that standard nominal .30 bullets pulled from water damaged .30-30 Winchester cartridges worked just fine in both .303 and 7.62X54r handloads. I suspect the .30-30 bullets were made fairly soft and bump up well when used in full power loads.

Of course these days .311 and .312 Jword bullets are not hard to find, the Honardy .312 bullets were in fact designed for the 7.7 Jap rifles, and cast boolits intended for the .303 should work very nicely.

Be sure the chamber neck is not too tight for a loaded cartridge with the larger diameter projectile.

[TCLouis]

Bruce

Yes when I bought it, the folks said they could not figure out the chambering. I was pretty smug and had assumed that it was rechambered to 300, imagine my surprise when I finally found some 300 brass and it did not work.
Cerro Safe will be my friend in this case.

It is good to get round to some of the collection of roundtoits.

The gunsmith that did the work, did it very well (wood and metal) so it should be "fun" once I figure it out.

[roverboy]

Let us know what you find out. It should make a good deer or other medium game rifle.

[bouncer50]

A good gunsmith would have stamp the barrel what it was rechamber for. But to guess is wrong, chamber cast is your best bet. And slug the bore the Japs are from 310-318 bore size

[funnyjim014]

I always love me a good mystery lol.

[runfiverun]

300 savage and still a 311 barrel.
common back in the day.
you just cut off part of the chamber and re-thread a new shank and screw everything back together then clean it all up.
the rifle still looks like it's "factory fresh".
the hornady 312 150gr bullet on top of Accurates 2700 will get you right close to 308 performance.
the feeding of more than one other round can be hit or miss since most converters left out the addition of a magazine block.

[Earlwb]

I would suggest using Cerrosafe and making a chamber cast to see what you have.
I sporterized one of my Type 99's into a .22-250 Ackley Improved varmint gun. So one needs to check as it could have been chambered for most anything actually.

[TCLouis]

Tomorrow I will search for the Cerro Safe and see if I can make a cast . . . .

Oh no I may have to figure out how to post a picture here after doing that.

It is "typical Japanese" profile and witness marks align.

I thought they had taken one of the type 38 barrels that the Chinese had rebored to 7.62X39 and put it on a type 99 action Whatever I find with the cast it seems the gunsmith modified and highly polished the feed ramps to improve feeding. I like a mystery and I LOVE a gun that sends a boolit where I point it, side by side with the one before and also the one after.

Wanta start a pool to guess what it finally turns out to be?

[rhbrink]

:coffeecom

[roverboy]

Tomorrow I will search for the Cerro Safe and see if I can make a cast . . . .

Oh no I may have to figure out how to post a picture here after doing that.

It is "typical Japanese" profile and witness marks align.

I thought they had taken one of the type 38 barrels that the Chinese had rebored to 7.62X39 and put it on a type 99 action Whatever I find with the cast it seems the gunsmith modified and highly polished the feed ramps to improve feeding. I like a mystery and I LOVE a gun that sends a boolit where I point it, side by side with the one before and also the one after.

Wanta start a pool to guess what it finally turns out to be?

I'm gonna say either a .300 Savage or .308 Win. But, like most times, I'm probably way off base.

[swheeler]

I think it is the std Jap 7.7 with a separated case in the chamber. By separated case I mean the neck portion is still in there and the rest extracted.;-) I will wait for Louis to give his final answer though!!

[ukrifleman]

If you have access to a copy of Lee's modern Reloading, you can compare your cast against the cartridge drawings shown as they are full size and should help to determine what calibre you have.

ukrifleman.

[Earlwb]

I think it is the std Jap 7.7 with a separated case in the chamber. By separated case I mean the neck portion is still in there and the rest extracted.;-) I will wait for Louis to give his final answer though!!

That is a really good point. This could be it. I have seen it happen before but I forgot about it until you mentioned it.

[swheeler]

Either Louis didn't find his cerrosafe or he is still taking measurements?

[3006guns]

I have a sporterized Jap type 99 chambered for 7.65 Mauser! If you compare the two cartridges they are almost identical.

The barrel was removed and the shoulder turned off just enough to allow it to thread in one more turn. Metal was then removed from the rear of the barrel and I don't think machining the extractor slot was even needed. The result is a handy rifle that will shoot corrosive surplus ammo all day and shrug it off because of the chrome plated bore.

This conversion was done in the early sixties and might be what you have.

[swheeler]

I have a sporterized Jap type 99 chambered for 7.65 Mauser! If you compare the two cartridges they are almost identical.

The barrel was removed and the shoulder turned off just enough to allow it to thread in one more turn. Metal was then removed from the rear of the barrel and I don't think machining the extractor slot was even needed. The result is a handy rifle that will shoot corrosive surplus ammo all day and shrug it off because of the chrome plated bore.

This conversion was done in the early sixties and might be what you have.

Interesting, Nippo-tine 7.65:-) Louis must have got the cerrosafe casting stuck in the chamber! LOL Come on Louis enquiring minds want to know.:kidding:

[gwpercle]

Come on TC.....the suspense is killing me !!!!! what is it

[swheeler]

Come on TC.....the suspense is killing me !!!!! what is it

Louis must have forgotten he posted this here, or got onto a different project for now?

[Sur-shot]

I have owned two that were "sportarized" and the chambers were recut to 30-06 by just sticking a reamer into the chamber and letting the web blow out on a fired case. They shot OK for a .308 bullet in a .311 barrel. I paid $5 for the first one and put a Fajen sporter stock on it, then hunted with it all the time I was in HS, up in the far north woods.
Ed

[3006guns]

Interesting, Nippo-tine 7.65:-) Louis must have got the cerrosafe casting stuck in the chamber! LOL Come on Louis enquiring minds want to know.:kidding:

I posted that some time back, and forgot to mention that the two cartridge profiles, i.e. shoulder angles, etc. are almost identical. The only difference is the length and setting the barrel back one thread took care of that. My particular rifle was inlet into a nice custom stock and shoots well enough to take ground squirrels at 100 yards if I do my part.

[bouncer50]

I have owned two that were "sportarized" and the chambers were recut to 30-06 by just sticking a reamer into the chamber and letting the web blow out on a fired case. They shot OK for a .308 bullet in a .311 barrel. I paid $5 for the first one and put a Fajen sporter stock on it, then hunted with it all the time I was in HS, up in the far north woods.
Ed During the Korean war the US took 1000's of WW11 Japanese rifle and rechamber them to 30-06 and give them to the Korean troops. So its very possible that some of them made it back to the US. It was a cheap and simple job to do.

[3006guns]

During the Korean war the US took 1000's of WW11 Japanese rifle and rechamber them to 30-06 and give them to the Korean troops. So its very possible that some of them made it back to the US. It was a cheap and simple job to do.

Yes, and if you find one PM me. They have "3006" stamped in LARGE numbers on the side of the receiver and I'd love to find one for my collection. I don't know if the U.S. armorers bothered to set the barrels back or not before rechambering, but they were a quick way to arm the ROK troops in the early fifties.

[dualsport]

I have a 99 rechambered to 30-06. It shot ok but the magazine length was a problem. Sooo, I put a .308 W chamber adaptor in there. Bingo. Shot alright and over all length was not a problem. Now I want that adaptor out of there and it's not budging. Tried the usual methods. It's really stuck good. Ideas?

[3006guns]

I have a 99 rechambered to 30-06. It shot ok but the magazine length was a problem. Sooo, I put a .308 W chamber adaptor in there. Bingo. Shot alright and over all length was not a problem. Now I want that adaptor out of there and it's not budging. Tried the usual methods. It's really stuck good. Ideas?

By "the usual methods" I assume you tried a broken shell extractor? I think that's how they were supposed to be removed. The only other method I can think of is to use an appropriate sized tap and thread it carefully into the adapter, leave the tap in place then knock it out from the muzzle with a 1/4" brazing rod.......which of course will ruin the adapter.

[dualsport]

Thanks for the idea. Haven't thought of that. I'll look at my taps for a fit. It actually functions as a magazine fed .308 w. so I'm tempted to leave it. But, the bolt closes with some resistance on factory ammo and I'm concerned the adaptor may move sometime down the line and disable the thing completely.

[swheeler]

Shameful bump, but it has been over a month?:???:

[rhbrink]

:coffeecom

[swheeler]

We'll just call it the two month bump. I hope it doesn't take nine months for this to hatch!:-)

[TNsailorman]

Although I have never actually had opportunity to see one of the type 99's chambered to the 30-06 case, I do remember seeing gunsmiths advertise doing this in the late 50's and very early 60's. But they also would say that the action needed a little work to get the magazine to work with the longer case. In this case a 7.7-06. One of our local gunsmiths also re-chambered some of the 6.5x50 rifles to the .257 Roberts case for a 6.5X.257 hybrid. It was the late 60's or early 70's before 6.5x50 and the 7.7 ammo started slowing being available. Dies were hard to find also. Ramblings of a very old memory, james