6.5 Japanese Pressures ?

22 May 2002, 19:49

<Paladin>

I don't think there is a SAAMI rating for the 6.5mm Jap.

Beyond that, last year I loaded a batch for a relative and tried to duplicate the original military loading. I was surprised to learn the original military loading is very mild and slow. On that basis, my impression is the 6.5mm Jap is a relatively low pressure cartridge, as originally loaded.

23 May 2002, 01:23

Rich Jake

Thanks I was pretty sure the it was a low pressure load but was tring to find out about where it was operating at.
Rich Jake

23 May 2002, 08:42

curley

Rich Jake, both you and Paladin are correct. An old NRA manual lists the 6.5 MM Arisaka as originally loaded with a 162 gr. FMJRN bullet at 2300fps, and later, a 139gr. FMJ pointed bullet at 2500fps, both at 38,000 psi.
Hope this helps.
Regards, Curley

[This message has been edited by curley (edited 05-22-2002).]

23 May 2002, 08:54

Rich Jake

Yep that helps. I was just trying to find out approximately what pressures it operated at. Thanks for the help!I didn't think it would be that difficult to find a pressure rating for a older cartridge like that.
Rich Jake

23 May 2002, 09:29

carcano91

Sure there is. I wonder nobody named it. The CIP maximum use pressure for the 6,5 x 50 SR is 2600 bar (silly low figure, probably because of Mod. 30 and 35 rifles ?), while the 7,7 x 58 is listed at 3100 bar. Both measured under the old copper crusher system, piezo pressures are higher of course. The actions, being the strongest of all military rifles, can take much more.

Regards, Carcano

23 May 2002, 09:40

Rich Jake

Ok ! You guys gave me exactly what I needed. Thanks to everyone for the help. It's great to be able to get answers like this.
Rich Jake

23 May 2002, 12:16

TCLouis

Accurate Arms Lists the fact that Norma factory ammo did not exceed 40,000 PSI in their test barrel.
Pretty light for the Type 38 in good shape.
Anyone out there with a type 38 that has a decent "round" chamber?
LouisB

23 May 2002, 22:02

Rich Jake

Thanks Louis
Rich Jake

26 May 2002, 13:47

carcano91

quote:
Originally posted by carcano91:
The CIP maximum use pressure for the 6,5 x 50 SR is 2600 bar (silly low figure, probably because of Mod. 30 and 35 rifles ?), while the 7,7 x 58 is listed at 3100 bar. Both measured under the old copper crusher system, piezo pressures are higher of course.

As I remember now dimly, the piezo quar(t)z figure for the 6,5 x 50 SR is about 2950 bar.

Regards,
Carcano

26 May 2002, 14:22

Pecos41

Interesting thoughts on the Jap rifles. But let me tell you a story related to me by my gunsmith, a graduate of the gunsmithing school in Trinidad, Colorado, and not just a tinkerer with a sign in the window.

He said one day a fellow came in and donated several Jap rifles to the school for them to do whatever they wanted with. Everyone thought they were junk and wouldn't mess with them.

Then one day my friend and another guy decided they would just take them out and blow them up for the fun of it. They loaded some ungodly something or other, even used the wrong sized bullet. Then went out and secured the gun over behind a log and fired it with a lanyard. After the earth shattering boom they went and looked over the log to find the stock busted and the barrel split and the Jap action still there and more or less functioning!

Point being, a lot of the Jap actions were hell for strength! I don't have a clue what the Japanese military loaded these cartridges up to and probably neither do the powder companies. So naturally they cut way back and err on the side of caution. But I've always been told the Jap action is one of the strongest bolt actions going. I've seen several converted to .308 winchester cartridge and doing just fine.

Perhaps someone with more technical expertise can chip in on this topic?? These are just my observations. [Smile]

[ 05-26-2002, 05:24: Message edited by: Pecos45 ]