Rechamber a 6.5 Arisaka to 6.5 Grendel

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Ivy Mike

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Quarantine does funny things to a person with lots of time and not much money for expensive rare ammo. I was looking at my old Type 44 6.5mm Japanese carbine and at ammo prices. I've shot the gun before and she's a great shooter, but ammo cost and spotty availability has made it a bit of a safe queen. I discovered that 6.5 Grendel shares some cases dimensions with the 6.5 Arisaka round, specifically, they are very close in terms of rim diameter, base diameter and they use the same size bullets. 6.5 Grendel is a hell of a lot cheaper than 6.5 Arisaka.
To my eye, it appears that one could use a Grendel reamer on the Arisaka chamber and shorten the chamber, rethread it and have a very nice shooting classic rifle with the benefit of modern ammo that is, ballistically, pretty close to the cartridge it replaced.
I've included drawings of the two cartridges and I think I may actually have an answer to that old question of what to use if you want to rechamber an old Arisaka rifle. Pressures for the Grendel are higher than the Arisaka, but that also may have to do with the older round being used in machine guns back then. The bolt rifles are plenty strong with people converting them to use necked-up .257 Roberts ammo without ill effects. I measured the thickness of the chamber walls and there is plenty of steel there. In fact, its thicker than my Yugo Mauser in 8mm Mauser.

What do you guys think? I am not a gunsmith but it looks to me like this could be a very straight-forward conversion. The extractor might need a little work and perhaps a change to the magazine floorplate to aid in feeding from the factory magazine with the shorter cartridge.
arisaka-dimension.png grendel-dimension.png
 
If your Arisaka is original your probably better off selling it to a collector and just getting a modern rifle. Type 44 arent that common and fetch pretty high prices. jmo
It doesn't have a mum and the bayonet lugs and pieces have been ground off.
It's not original.
 
Wow, sounds alot easier than I would have guessed.

Since it's not a collector, I say go for it if you know a gunsmith/machinist who can spot ya.

This is going to be an idea that I have no experience nor knowledge about other than it's existence.... There used to be companies that sold plugs or spacers, basically chamber wedges that you would locktite into an action for old surplus guns to convert calibers. I wanna say there was a 30-06 to 7.62x39 one or something. Don't know if they still exist or were dangerous.

But, it might be something to make a chamber mold first to see if it's viable before taking a cutter to the barrel
 
Since I'm not well versed in either round I would ask what weight bullets each is commonly loaded with and what twist rate in the barrel. If incompatible you would have a gun that might chamber and fire OK, but produce miserable accuracy. If they are compatible, then the rest is "gnsmiffin'".

… perhaps a change to the magazine floorplate to aid in feeding from the factory magazine with the shorter cartridge.

More likely have to shorten the follower, use a different mag spring, and put a spacer in the back of the magazine. Possibly some feed rail work, too.
 
Since I'm not well versed in either round I would ask what weight bullets each is commonly loaded with and what twist rate in the barrel. If incompatible you would have a gun that might chamber and fire OK, but produce miserable accuracy. If they are compatible, then the rest is "gnsmiffin'".



More likely have to shorten the follower, use a different mag spring, and put a spacer in the back of the magazine. Possibly some feed rail work, too.
6.5 Arisaka is almost 1 in 9", likely whatever the metric equivalent to 9" is. A Sierra reloading manual says 1 in 9". 6.5 Grendel is 1 in 8" or 1 in 9" depending on the bullet weights you want. They are compatible if you use heavier bullets which the Arisaka cartridge does. 130-140 grain bullet weight.
I said floorplate in my other post, but meant follower like you said. The follower is just a flat piece of steel and the feed "ramp" is little more than a speedbump to nose the bullet into the chamber. I'm thinking it won't take much tweaking at all.
 
It would be a good DIY if you had a lathe to set back, thread, and rechamber the barrel. You could rent a reamer.

A full time gunsmith would charge hundreds of dollars for such work.
yeah, I'm anticipating having to take it to a gunsmith for this. I don't have a lathe or the tooling to do this.
 
You know, there's only one way to find out....

It sounds like a cool project. I admit, my initial reaction is to not mess with an old war rifle but if you're going to keep it, you might as well make it a shooter.

On the other hand, I just got back from the range with my 6.5 Carcano. I started loading my own a long time ago. Dinging the poppers at 100 yards sure is fun.
 
I reload for the 6.5 Arisaka and the only price difference between it and 6.5 Grendal is a little more powder and a little more for the 140gr bullets, the pleasure shooting it far exceeds the small price difference.
I agree with the earlier post about selling it and getting something more modern that will be a LOT easier to mount a scope, I would think by the time you pay a gunsmith to modify your barrel, you will be money ahead with a bolt action or AR, personally if doing a bolt action I don't know if 6.5 grendel would be my first choice, its appeal is being able to fit in AR mags.
 
Difference rim size; different length; would require extensive work to the bolt face; either remove, cutoff, and rechamber the original barrel; replace it and rechamber. Or make a chamber adapter... You are either going to have the skills for a conversion or hire a gunsmith.
My suggestion is to get some brass and a set of dies and reload. Or sell it and buy a shooter.

Just my two cents.
 
Difference rim size; different length; would require extensive work to the bolt face; either remove, cutoff, and rechamber the original barrel; replace it and rechamber. Or make a chamber adapter... You are either going to have the skills for a conversion or hire a gunsmith.
My suggestion is to get some brass and a set of dies and reload. Or sell it and buy a shooter.

Just my two cents.
The difference in rim size might require a little work to the extractor. The Chinese did a very similar caliber conversion decades ago with minimal or no changes to the bolt face. They used 7.62x39 and SKS barrels. The few videos on YouTube show these rifles working quite well as long as you're smooth with the bolt; ejection being the questionable aspect rather than extraction. Some rifles had their followers modified while others did not.

I'm guessing the safer bet is cut off some or all of the threads, ream out the chamber and rethread. A chamber adapter could work but might leave excessive freebore. The barrel on mine is pretty nice for a service rifle. It would take some measuring to be sure or see if it even matters.

Reloading would require I purchase several hundred dollars worth of equipment I do not presently own.
 
I'll bet you could start reloading 6.5 Arisaka for less than the machine work would cost.

I second this.

The difference in rim size might require a little work to the extractor. The Chinese did a very similar caliber conversion decades ago with minimal or no changes to the bolt face. They used 7.62x39 and SKS barrels. The few videos on YouTube show these rifles working quite well as long as you're smooth with the bolt; ejection being the questionable aspect rather than extraction. Some rifles had their followers modified while others did not.

I'm guessing the safer bet is cut off some or all of the threads, ream out the chamber and rethread. A chamber adapter could work but might leave excessive freebore. The barrel on mine is pretty nice for a service rifle. It would take some measuring to be sure or see if it even matters.

Reloading would require I purchase several hundred dollars worth of equipment I do not presently own.

It looks like you have done a lot of research. I think the 6.5 CM is a fun little cartridge. It would be interesting to see how it performs in a rifle that was designed 100 years ago. If you go through with it post the rebuild and the results.
 
I'll bet you could start reloading 6.5 Arisaka for less than the machine work would cost.

Agree.
The long long lists of equipment you see on the www and the "kits" sold as package deals are luxury level.
All you really need is a press and dies. The Lee dies come with a powder dipper that will give you safe but not exciting loads.
 
The 6.5 Arisaka is a rather pleasant round that has the dubious problem of being a cartridge designed, like the Krag, Mauser cartridges before 1905, etc. during the transition from black powder to smokeless powder. It is effective enough for what it is designed for and for woodlands hunting. The problem was that a) no brass to reload for a very long time, b) expensive out of spec 6.5 Arisaka brass from Norma. However, when Prvi started reloading this and provided brass, then it is practical to again fire it in the original cartridge.

I have a couple of them in military trim and in the full length rifle, recoil is negligible. In the carbine, a bit more but not excessive. Reloading dies, bullets, and brass are around (try Grafs and Sons as they consistently keep old milsurp ammo and brass in stock). It is not problematic to load (avoid Norma brass unless they've fixed their specs), and shoots fine in the 100-200 yard range.

Some folks, in order to be able to shoot their rifles when the surplus Japanese ammo dried up, rechambered them into a wildcat 6.5x257 (akin to the .257 Roberts) to a varying effect. Not all of these conversions are marked so if in doubt, check your chambers before firing.

Here's a thread about it,
https://www.gunandgame.com/threads/6-5-x-257-conversion-on-an-arisaka.161823/
 
The 6.5 Arisaka is a rather pleasant round that has the dubious problem of being a cartridge designed, like the Krag, Mauser cartridges before 1905, etc. during the transition from black powder to smokeless powder. It is effective enough for what it is designed for and for woodlands hunting. The problem was that a) no brass to reload for a very long time, b) expensive out of spec 6.5 Arisaka brass from Norma. However, when Prvi started reloading this and provided brass, then it is practical to again fire it in the original cartridge.

I have a couple of them in military trim and in the full length rifle, recoil is negligible. In the carbine, a bit more but not excessive. Reloading dies, bullets, and brass are around (try Grafs and Sons as they consistently keep old milsurp ammo and brass in stock). It is not problematic to load (avoid Norma brass unless they've fixed their specs), and shoots fine in the 100-200 yard range.

Some folks, in order to be able to shoot their rifles when the surplus Japanese ammo dried up, rechambered them into a wildcat 6.5x257 (akin to the .257 Roberts) to a varying effect. Not all of these conversions are marked so if in doubt, check your chambers before firing.

Here's a thread about it,
https://www.gunandgame.com/threads/6-5-x-257-conversion-on-an-arisaka.161823/

This rifle was my grandfather's that he brought home. It's in 6.5x50. I actually still have the papers on it, my 7.7mm type 99, bayonets for both (I can't mount the type 44 though) and an NCO's katana.
 
This rifle was my grandfather's that he brought home. It's in 6.5x50. I actually still have the papers on it, my 7.7mm type 99, bayonets for both (I can't mount the type 44 though) and an NCO's katana.
If you have provenance like that, then don't convert it. Even as it is, war trophies bring a premium over a std. one. That letter makes it more collectible along with the bayonets. There are still bayonet mount and lugs that come up for sale every so often on ebay or gunbroker. Put an automated search on it and get one when available but figure out which one was original--there were several T44 bayonet mounts from my recollection.

Buying a bayonet mount is cheaper than having a gunsmith convert it.
 
If you have provenance like that, then don't convert it. Even as it is, war trophies bring a premium over a std. one. That letter makes it more collectible along with the bayonets. There are still bayonet mount and lugs that come up for sale every so often on ebay or gunbroker. Put an automated search on it and get one when available but figure out which one was original--there were several T44 bayonet mounts from my recollection.

Buying a bayonet mount is cheaper than having a gunsmith convert it.
It's the 1st pattern.
 
It's the 1st pattern.
Given that you have several items, you might actually contact someone like Simpson's Ltd. or Joe Salter to see what they would pay as is. A true collector with a gap might just be willing to wait a while to get a bayonet mount if they could get a Type 44 with all the rest of it intact where all they needed was the mount. Could put it on consignment. Or simply watch and wait via automated alerts for a type 44 bayonet mount. They do come up from time to time. I have seen about 3-4 offered at auction over the last 3 or 4 years. I track the T 44 as I have a stock and some other stuff but decided not to do any more military restorations for the time being until I finish current projects.

I have also hit it lucky with using Ebay's vintage rifle parts as stuff shows up there when people do not know what they have. You can sort for new listings only. Gunbroker parts sellers usually know what they have.
 
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