6.5 Jap service rifle vrs 6.5 Arisaka... anyone play ???

Magnum Wheel Man · August 16, 2011, 02:16 PM

I couldn't get a response to my last thread, so I'm wording differently

I just got a model 38 carbine in 6.5 mm the guy I bought it from is a retired tool & die / gun smith... he made a set of custom dies ( the chamber is both longer & over .010" bigger in diameter than the Arisaka cartridge ) he's calling it 6.5 mm Japanese service cartridge... ( he appearently found the dimensions in one of his books )

he's also made a forming die to form 35 Remington ( though they'll be just less than 1/8" shorter in the neck ) & is taking the rim off some 303 British to make me some longer cases in case I wanted to load hotter loads ( he's concerned that using "regular" Arisaka cases will cause short case life because of the bigger chamber diameter ) personally I probably will just load up the cases I have, shoot it a little, & put it in my service rifle locker... butt... maybe I'll take a liking to the carbine & cartridge, & start shooting it more ???

anyone out there pretty knowledgable of the Jap cartridges ???

want to talk reloading while I'm obsorbing all this new data ???

**Mike Irwin** · August 16, 2011, 02:25 PM

Jap service cartridge?

Huh?

The Japanese adopted the 6.5x50SR Arisaka cartridge around 1905 and never looked back. That is the ONLY 6.5 cartridge the Japanese ever used for its military.

I THINK what your smith is calling the "6.5 mm Japanese service cartridge" is actually an American invention born of necessity in the post WW II era...

I'd bet money that that is a wildcat chambered in 6.5x257 Roberts. That was a very common way of making Type 38 rifles shootable. Some loading manuals had some data for that round in the 1950s, but it quickly fell by the wayside when Norma began making new 6.5x50 Arisaka brass and cartridges in the 1960s.

The 6.5x257 is a good cartridge. You can use .257 Roberts loading data, starting low and moving up.

Magnum Wheel Man · August 16, 2011, 02:37 PM

I'll check into that... my buddy found the Jap Service Cartridge case dimensions in an old handloading book... that's not to say the 257 Roberts cartridge is not what this rifle is now chambered for

it's also my understanding, that they used rather loose chamber dimensions possibly for battle conditions, maybe they needed the looser chambers in their auto guns for function, & standardized loose ???

either way, the custom dies more closely match the chamber dimensions...

I'm at work, & don't have my books here... does the 257 Roberts & 35 Remington have the same rim diameter ??? the 35 Remington cases function perfectly in the mag & through the chamber & extractor, when I fire formed the shoulders of the resized cases

tater134 · August 16, 2011, 03:54 PM

Quote:

I'm at work, & don't have my books here... does the 257 Roberts & 35 Remington have the same rim diameter ??? the 35 Remington cases function perfectly in the mag & through the chamber & extractor, when I fire formed the shoulders of the resized cases

.35 Remington cases can be reformed into 6.5jap if you run them through a .308 die and then into a 6.5jap die. The rim diameter is slightly smaller than the 6.5 and the cases will be a little bit short after reforming. A lot of 6.5 Arisakas were rechambered to .257 roberts after the war because of the scarcity of 6.5jap ammo so its possible that your rifle has been rechambered to that caliber.

F. Guffey · August 16, 2011, 04:50 PM

Quote:

Originally Posted by fguffey

And I have a 6.5mm257 Roberts Japanese dies, forming die and a chamber reamer, in the old days the 6.5mm50 was chambered to 6.5mm 257 Roberts Japanese.

F. Guffey

The dies and reamer are labeled 6.5mm257 Roberts Japanese.

**Mike Irwin** · August 16, 2011, 09:36 PM

"does the 257 Roberts & 35 Remington have the same rim diameter ???"

No.

.257 Roberts is based on the 7mm Mauser, which has a rim/base diameter of (nominally) .470, same as the .30-06.

6.5 Arisaka has a rim diameter of .466, and a base diameter of .447.

.35 Remington has a rim diameter of .460, and a base diameter of .458.

It's possible that someone reamed out the chamber to take reformed .35 Remington. The .35 case is too short by 3mm, but the shoulder is in the same place as the 6.5 Arisaka, so headspace wouldn't be an issue.

I've never heard of anyone doing this, though. By far the most common conversion as 6.5x257 Roberts.

Before you do anything you ought to have a chamber cast done.

Scorch · August 17, 2011, 12:35 AM

Quote:

6.5 Jap service rifle vrs 6.5 Arisaka...

Same same.

Do a chamber cast. If it is still chambered for 6.5X50mm, just buy some Norma ammo and reload it. Your chamber is probably just oversize/sloppy, like many military arms. Just neck size the brass and no problems with working it too much.

Reforming 35 Rem is a pain, and your cases will have short necks, but it is an acceptable workaround in case you can't get cases.

armsmaster270 · August 17, 2011, 01:33 AM

I just shoot my 6.5 type 38 with factory loads.

tater134 · August 17, 2011, 09:21 PM

Quote:

Do a chamber cast. If it is still chambered for 6.5X50mm, just buy some Norma ammo and reload it.

I would save my money and get different brass to reload if you can find it. The Norma brass I had was undersized and bulged badly when fired. I did a search the net after I saw the bulged cases and other shooters had the same problem with Norma brass. I don't know if they've corrected the problem but there is cheaper brass and ammo out there.

August 16, 2011, 02:16 PM	#1
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	6.5 Jap service rifle vrs 6.5 Arisaka... anyone play ??? I couldn't get a response to my last thread, so I'm wording differently I just got a model 38 carbine in 6.5 mm the guy I bought it from is a retired tool & die / gun smith... he made a set of custom dies ( the chamber is both longer & over .010" bigger in diameter than the Arisaka cartridge ) he's calling it 6.5 mm Japanese service cartridge... ( he appearently found the dimensions in one of his books ) he's also made a forming die to form 35 Remington ( though they'll be just less than 1/8" shorter in the neck ) & is taking the rim off some 303 British to make me some longer cases in case I wanted to load hotter loads ( he's concerned that using "regular" Arisaka cases will cause short case life because of the bigger chamber diameter ) personally I probably will just load up the cases I have, shoot it a little, & put it in my service rifle locker... butt... maybe I'll take a liking to the carbine & cartridge, & start shooting it more ??? anyone out there pretty knowledgable of the Jap cartridges ??? want to talk reloading while I'm obsorbing all this new data ??? __________________ In life you either make dust or eat dust...

August 16, 2011, 02:25 PM	#2
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,381	Jap service cartridge? Huh? The Japanese adopted the 6.5x50SR Arisaka cartridge around 1905 and never looked back. That is the ONLY 6.5 cartridge the Japanese ever used for its military. I THINK what your smith is calling the "6.5 mm Japanese service cartridge" is actually an American invention born of necessity in the post WW II era... I'd bet money that that is a wildcat chambered in 6.5x257 Roberts. That was a very common way of making Type 38 rifles shootable. Some loading manuals had some data for that round in the 1950s, but it quickly fell by the wayside when Norma began making new 6.5x50 Arisaka brass and cartridges in the 1960s. The 6.5x257 is a good cartridge. You can use .257 Roberts loading data, starting low and moving up. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

August 16, 2011, 02:37 PM	#3
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	I'll check into that... my buddy found the Jap Service Cartridge case dimensions in an old handloading book... that's not to say the 257 Roberts cartridge is not what this rifle is now chambered for it's also my understanding, that they used rather loose chamber dimensions possibly for battle conditions, maybe they needed the looser chambers in their auto guns for function, & standardized loose ??? either way, the custom dies more closely match the chamber dimensions... I'm at work, & don't have my books here... does the 257 Roberts & 35 Remington have the same rim diameter ??? the 35 Remington cases function perfectly in the mag & through the chamber & extractor, when I fire formed the shoulders of the resized cases __________________ In life you either make dust or eat dust...

August 16, 2011, 09:36 PM	#6
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,381	"does the 257 Roberts & 35 Remington have the same rim diameter ???" No. .257 Roberts is based on the 7mm Mauser, which has a rim/base diameter of (nominally) .470, same as the .30-06. 6.5 Arisaka has a rim diameter of .466, and a base diameter of .447. .35 Remington has a rim diameter of .460, and a base diameter of .458. It's possible that someone reamed out the chamber to take reformed .35 Remington. The .35 case is too short by 3mm, but the shoulder is in the same place as the 6.5 Arisaka, so headspace wouldn't be an issue. I've never heard of anyone doing this, though. By far the most common conversion as 6.5x257 Roberts. Before you do anything you ought to have a chamber cast done. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

August 17, 2011, 01:33 AM	#8
armsmaster270 Senior Member Join Date: November 25, 2008 Location: California Posts: 1,951	I just shoot my 6.5 type 38 with factory loads. __________________ http://www.armsmaster.net-a.googlepages.com http://s239.photobucket.com/albums/f...aster270/Guns/ Retired LE, M.P., Sr. M.P. Investigator F.B.I. Trained Rangemaster/Firearms Instructor & Armorer, Presently Forensic Document Examiner for D.H.S.