Arisaka: correct caliber issue

[dh1633pm]

No problem. My thought process is if it would fit empty that you could fire form by using the instructions for this. I have done it before with a small amount of pistol power, then a filler and something to hold it all in. Makes a nice brass copy of the chamber. No worries. I hope your able to figure it out.

 

[Heir Kommt Die Sonne]

I hope your able to figure it out.

UPDATE: I think it's a .280 Ackley Improved. I got a reloading manual today and was comparing to the different calibers. This case best matches that of .280 Ackley improved.
I wish there was more Ackley Improved cartridges listed in this manual, but I'm betting on .280 because when we fired the 7.7 jap casing in this rifle we had a severe sticky bolt - so I'm thinking it was probably due to too big a bullet going down the barrel. Could that cause a bolt to seize up?

 

[LoonWulf]

Could that cause a bolt to seize up?

That would be a fairly minor side effect of firing a 7.7 and a 280 Ackley chamber lol....

 

[LoonWulf]

Your gun LOOKS to have the original barrel on it though, so at the very most it would mean a rechamber unless somebody went to a lot of effort to duplicate the same profile as the military barrel which strikes me as being highly unlikely.

I think the two cartridges you're likely to see are either the 30-06 AI or the 30 Gibbs


If compared to a standard 30-06....
The Gibbs would have pushed the whole shoulder forward and noticeable amount, The '06 AI would leave the neck junction and basically the same place but push the rear of the shoulder forward to sharpen the angle.

 

[Heir Kommt Die Sonne]

so at the very most it would mean a rechamber unless somebody went to a lot of effort to duplicate the same profile as the military barrel which strikes me as being highly unlikely.

Thats the thing that still confounds me, of ALL calibers to rechamber a Arisaka for, a 30.06 would make the most sense. And hundreds of them were converted to 30.06. The reason this one had to be some different caliber confuses me. But nonetheless i will keep trying.

30-06 AI or the 30 Gibbs

Does anyone have a picture of a 30.06 next to a 30.06 AL and a 7.7 Jap?

 

[Steel Horse Rider]

A reloading manual would answer your questions about case sizes and calibers without buying more cartridges. A caliper or micrometer would be a great help inn getting an accurate measurement of your fire formed case.

 

[LoonWulf]

Thats the thing that still confounds me, of ALL calibers to rechamber a Arisaka for, a 30.06 would make the most sense. And hundreds of them were converted to 30.06. The reason this one had to be some different caliber confuses me. But nonetheless i will keep trying.


Does anyone have a picture of a 30.06 next to a 30.06 AL and a 7.7 Jap?

I'll dig through my cases and see if I can come up with them I did have all of them at one point in time.

Just to clear up the board diameter question can you try poking a 7.7 mm bullet into the fire formed casing?
I'm almost 100% positive your barrel is still in .31some odd. Shoving a 77 bullet into it with little or no resistance would support that theory, and the theory that the chamber is likewise somewhere around a 30 caliber cartridge.

 

[LoonWulf]

So it appears ive finally managed to divest myself of all my .30-06 and 7.7 brass. All I could find was a 30-06AI

 

[SKS_Fiend]

{DELETED}

 

[troy fairweather]

Kinda looks like a 30 Gibbs.

 

[DocRock]

Cerosafe will answer these questions.

 

[entropy]

View attachment 956850 That's interesting. The only thing that comes to my mind is 7.7 Ackley Improved. For comparison here's a picture of a 7.7 on the left and .30-06 on the right.

It sure looks like .30 Gibbs, but that's because the case is only 58mm long.
Chamber casting time. Keep us posted.

 

[BJung]

Attached is a photo of a 30-06 case that's been resized through a 7.7 x 58 Arisaka die next to a trimmed and fireformed case. I think your rifle has been rechambered. I want to say it's a 30-06 except that the shoulder is too round. To check your bore, find a fisherman with a split shot that's close to the bore, grease it, and drive the lead through the barrel with a wooden dowel, then measure the diameter of the lead slug. Given a stock barrel, the difference between a 7.7 and 6.6 bore is obvious.

 

[Heir Kommt Die Sonne]

I don't think it's .30 Gibbs because the parent cartridge, a 30.06, won't let the bolt seat down.

 

[bullpup-addict]

I don't know if this will help but here goes.

 

[DocRock]

Don't know much about Arisakas. Is it a CRF? If so, the extractor won't slip over the rim of a cartridge laid in the cartridge follower (ie single loaded), so the bolt wouldn't close on a 30-06 case. Try pushing the 30-06 down into the magazine and then closing the bolt. It may pick the cartridge up and close.

 

[LoonWulf]

Heres 06AI and .280AI compared to a .308....might be able to reference that against your 308/7.7 comparison....(somehow managed to forget to attach the photo)

Also as a note, if it WAS reamed ro 06AI, closing the bolt handle will possibly take some force, since a "crush fit" on factory rounds was desired for fire forming, some one with a reamer and an old cartdidge.... especially if they were using the same one over and over, may have ended up with a chamber on the short side.
The Arisaka i had an issue with was reamed to 30-06 but left very short, and would only close on new factory ammo with a noticeable amount of effort.

And an chamber cast is sill the right answer lol.

also found this picture showing the difference between a gibs, AI, and regular 06

 

[GooseGestapo]

The Arisaka is definitely a Mauser derivative that is CRF (controlled feed round).
I’m betting that it’s a 7.7x63 AI. (7.7-‘06 Ackley Improved).

I recently had an acquaintance bring me an Arisaka, wanting ammo. I ordered 50rds of brass and dies. First firing, “UH-OH!”!!!
7.7-06! I pulled the ammo, reseated the bullets in ‘06 cases.
The rifle shoots AMAZING! 2.5” @100yds groups easy with open sights.
Hornady.312” 150gr bullets over H4895.

 

[mokin]

The Arisaka is definitely a Mauser derivative that is CRF (controlled feed round).
I’m betting that it’s a 7.7x63 AI. (7.7-‘06 Ackley Improved).

I recently had an acquaintance bring me an Arisaka, wanting ammo. I ordered 50rds of brass and dies. First firing, “UH-OH!”!!!
7.7-06! I pulled the ammo, reseated the bullets in ‘06 cases.
The rifle shoots AMAZING! 2.5” @100yds groups easy with open sights.
Hornady.312” 150gr bullets over H4895.

You gotta love those old rifles!

 

[Heir Kommt Die Sonne]

Cerosafe will answer these questions.

I just bought half a pound of Cerrosafe. It's better to spend 20 dollars once and to be safe than it is to buy different cartridges trying to see which one fits.
The manual I need now is Calibers of the world ,correct?

 

[LoonWulf]

I just bought half a pound of Cerrosafe. It's better to spend 20 dollars once and to be safe than it is to buy different cartridges trying to see which one fits.
The manual I need now is Calibers of the world ,correct?

I think I've got an old version I can send you let me look when I get home from work.

You can look up all the specifications for the cartridges online also.

 

[Heir Kommt Die Sonne]

I think I've got an old version I can send you let me look when I get home from work.

Does it also have load information?

 

[wiscoaster]

Does anyone have a picture of a 30.06 next to a 30.06 AL and a 7.7 Jap?

Don't have any Jap loaded, but here's the casings side by side: 30-06 left and 7.7 x 58 right:
View attachment 1002032

 

[LoonWulf]

Does it also have load information?

If I remember correctly it has some..... I've also got a lyman 50 manual It has a reasonable amount of load information for a lot of cartridges

 

[Heir Kommt Die Sonne]

If I remember correctly it has some..... I've also got a lyman 50 manual It has a reasonable amount of load information for a lot of cartridges

Do you have a old lyman manual you don't need anymore?