Unknown chamber in my Arisaka!!

[texassako]

A 30-06 Lee collet neck sizer should work well on that, and pretty cheap as well. It does not put downward pressure on the shoulder, less chance of collapsing it than a bushing die. It squeezes shut on the neck to resize it on the mandrel. You can also substitute a .311 mandrel since it is pretty easy to mix and match with these for other calibers.

[wallenba]

A 30-06 Lee collet neck sizer should work well on that, and pretty cheap as well. It does not put downward pressure on the shoulder, less chance of collapsing it than a bushing die. It squeezes shut on the neck to resize it on the mandrel. You can also substitute a .311 mandrel since it is pretty easy to mix and match with these for other calibers.

I concur. I took a look into my Lee 308 Win. collet neck sizer. It's completely open around the shoulder.
I talked to the pros at D & D Gunsmiths at Troy Mi. this week. If I can obtain a good 7.7 Jap. Barrel, I just might reverse this turkey. Options still being considered.

[wallenba]

It looks to me like the 30-06 JDJ is another possibility. Here's the drawing of it: http://ammoguide.com/?catid=528 John Sundra also made some wildcats on the 30-06 case with the shoulder blown forward.

I looked into this possibility this morning. The link would not allow me to get anything without joining up. Feeling lazy I called SSK Industries. Actually talked to J.D. himself I do believe. He said if it was a 30-06 JDJ, he would have done the mod himself since he does not provide reamers. Also the fact it's not marked on the rifle means it's not his work. But it does look eerily similar.

[Pirate69]

The Arisaka is one tough action, only incidents of kabooms I've heard of was when some kids fired three rounds of .35 remington though a 7.7 with the receiver letting go on the third shot putting fragments in the shooter's brain, and one gunsmith reported having accidentally put a 7.92 cartridge in a 7.7 when firing remotely in a testing booth.
Chamber neck clearace is more important than bullet to bore fit, so I'd be very careful to find out the chamber neck ID before doing much shooting.


Theres been a reported instance of a 6.5 rifle rechambered to .30-06 by someone who did not realize the true bore size.
Could be someone thought the bore was 7mm rather than 7.7mm.

I think this is from the May, 1959 edition of the American Rifleman, page 52. At least that is what is reported on page 93 of BOLT ACTION RIFLES by Frank de Haas; MCMLXXI. The guy actually used it hunting and killed a deer. Took it to a gunsmith to have checked out because the recoil was excessive. Gunsmith fired a number of 30-06 rounds in it after knowing the situation. Wonder how that testing was done; brave man? Rifle later sent to NRA for additional testing. The Arisaka is one tough action even if it is as ugly as they come.

[Char-Gar]

Here is my input. The shoulder of the fired case is rounded and not very Ackley like. There was a family of Wildcats based on the 06 case called "ICL" Increased Capacity Loading that had such a shoulder. Therefore a 30 ICL is my best guess.

[wolfwing]

9 y.o. post, but I vote for 30 Gibbs

[slim1836]

I wonder if the OP is still around, he was on here last on 03-15-2019.

Slim

[Soundguy]

I've seen 7.7 cut to 30-06. That shoulder almost reminds me if a 300 Weathery mag

[oldblinddog]

When looking at the cerrosafe cast (not matched up with the brass) it doesn’t look like a .30-06 is the parent case to me. The ..30-06 is not long enough.

[Soundguy]

Shoulder really.really looks like a wm

[bigdog454]

If you are going to get another barrel, you could change to anything that uses a 06 or08 dim case. I had one rechambered to 6.5 X308 that was a really great shooter (under moa) the 6.5 308 is now the 260. just saying.
BD

[john.k]

All the Type 99s Ive seen have a chrome plated bore....apparently this is the "Marine model"......anyhoo,rechambering a chrome bore must be hard on reamers ......I counterbored a muzzle on one as there was a bit rust lifting of the chrome in the muzzle ,took it back about 1"......didnt do the drill bit much good.