Graf and sons has the 7.7 Arisaka brass in stock... They have Hornady dies too...

 

The 7.7 was designed to be able to shoot and function with 30-06 ammo as the Japs wanted to be able to use munitions seized during WWII but not work the other way around. I don't suggest doing that as it may be functional but tremendously less than optimal and in a 80 year old rifle no need to push your luck. I have a friend who has a 7.7 he was gifted from his Grand dad and he uses the 30-06 brass himself and reshapes them with sizing dies accordingly. Personally I would go with the above mentioned advice and pay for the specific brass and go from there. Buy a hundred or two cases and with loads appropriate for that rifle you should get a good 8 to 10 reloads out of each.

There are reloading forums if you search for them and you would be able to find a number of threads on this very topic. Do a specific search for reloading 7.7 Jap with 30-06 brass.

 

The 7.7 was designed to be able to shoot and function with 30-06 ammo as the Japs wanted to be able to use munitions seized during WWII but not work the other way around.

No. Not at all. Case rim to shoulder on a .30-06 (7.62x63) is 1.9480". Case rim to shoulder on the 7.7x58 is 1.8720". If you tried real hard, you couldn't jam a .30-06 case into an Arisaka chamber. That extra 5mm of neck might hang up, too. Look up the case and chamber dimensions in Cartridges of the World, or SAAMI website. I refer you to COTW, DBI books, copyright 1972 pp. 179-205

This is a rumor that is 100% untrue. Maybe it's info from an old ARGOSY or TRUE article from 1946. Correction needed.

 

I have made 8mm Mauser out of 30-06 because it was laying around on the range and cheap. 7.7 Jap uses a 311 bullet over a 308. I decided it really was not worth it and bought 8mm Mauser brass. The 7.7 is 7.7X58 and the 06 is 7.62X62 so there is a case length difference, To get proper fit the Jap has to have the 11mm or .473 head , According to what I looked up the Jap is .470 so it may or may not fit he bolt face. Also the case is slightly shorter to the shoulder. Could be done if one just wanted a few cases to shoot it with but not ideal.
A lot of these old military rifles had pretty sloppy chambers and are best neck sized only for reloading after firing or you get case separation. Lyman loading manual also claimed they had a very variable bore from 311-317. I ran into a Russian carbine once that had a 317 bore. I would buy the cases and neck size only.

DEP

 

All you need to do is run the 30-06 through a 7.7 jap sizing die and trim to length. It will fit perfectly. It's quite a bit longer, so there is a lot of trimming. 7mm or 8mm Mauser is a lot closer in length, so less trimming.

 

Cartridge case dimensions, .30-06 Springfield and 7.7x58 Japanese.

 

Thanks for the clarification, Rob. I had heard this (rumor) since as far back as I could remember. Having exceptional examples of both an M1 Garand and Type 99 Arisaka I was never tempted to try it.
My first deer, at age 15 was killed with a 7.7 (with Mum) my USN fighter pilot father brought back from the Pacific theater. Below is a video from Sept 02, 1945, 25 years to the day I left RVN after 3 campaigns and one full tour. I will now wonder if the higher ups told this story about the captured ammo to the Japanese infantry!!! All being said the Arisaka is purported to be one of, if not the strongest action of any of the Allies weapons during the Big One. The finish on the "last ditch" models reminds me of Remlins, but the metal parts were purported to be equal to the transition period ones in structural integrity.

In deference to Land Cruiser, I would agree that it would not be prudent to try to adapt the 30-06. But then I am no expert.

 

During and after WW1, the Japanese bought a LOT of Lewis guns from Great Britain, and also acquired the rights to manufacture them. Soldiers from the Dutch East Indies, the Aussies, Chinese, the Brits, and Americans were killed and wounded by the Lewis guns. The Japanese seized more Lewis guns at the fall of Singapore. It was a very popular weapon with Imperial Japanese sea, land, and air forces. The caliber was 7.7x56R, better known to us as the .303 British. The Japanese had been making 7.7x56R ammunition since the teens, they were our allies in WW1. The various Japanese Marks and Mods are straight-up copies of British service .303 inch ammo. I've seen some, but never shot it.

 

Thanks guys for all the information!