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Arisaka Type 99 Conversion
- Thread starter Ilya5.7
- Start date
Jim Watson
New member
I don't think a 7.62 reamer would "clean up" a 7.7 chamber.
The barrel threads are different, you could not "just swap out the barrels".
Even if you put on a new barrel or set back the original to get a proper chamber, you would still have the problem of a tapered rimmed cartridge in a Mauser type staggered box magazine made for rimless.
The barrel threads are different, you could not "just swap out the barrels".
Even if you put on a new barrel or set back the original to get a proper chamber, you would still have the problem of a tapered rimmed cartridge in a Mauser type staggered box magazine made for rimless.
Blindstitch
New member
You probably have a reason for your choice but if you're a reloader why not ream to 30-06 and then get a larger .311 expander for your dies. But then again if you reload you probably already do 7.7.
Gunplummer
New member
Yes, did it twice. It is not for anybody that is inexperienced (That includes gunsmiths). You need to make a new bolt that has the locking head configuration of the Russian rifle. Now you have the little "finger" extractor which works well with rimmed cartridges. This causes other problems. Now you need a guide to replace the claw extractor. With out the claw extractor there is a spot where the bolt lugs can actually turn out of the broached area of the receiver. Take the extractor and collar off an Arisaka and try feeding dummies through.
I used to add a slug of Pre-heat 4140 to an Arisaka barrel (Or almost any barrel). This was threaded on and met in the middle of the neck area with a flat butt joint. You now have chamber area to work with.
I was never able to get a magazine set up for more than 3 in the box and one in the chamber. If you change the back of the magazine box so it is slightly tapered like a Mark III, you can avoid rim lock. I did one in 7.62x 54 and one in 8MMx54. They shot about like an average east coast hunting rifle. Nothing to write home about.
If you really want a painless conversion of an Arisaka, try .300 Savage. Set the barrel back a little and recut the chamber. You will have some feeding issues too, but can overcome them. I have owned a couple I picked up at yard sales and shows. Good little shooters.
Wow. Just looked at this post. Time to lay off the coffee.
I used to add a slug of Pre-heat 4140 to an Arisaka barrel (Or almost any barrel). This was threaded on and met in the middle of the neck area with a flat butt joint. You now have chamber area to work with.
I was never able to get a magazine set up for more than 3 in the box and one in the chamber. If you change the back of the magazine box so it is slightly tapered like a Mark III, you can avoid rim lock. I did one in 7.62x 54 and one in 8MMx54. They shot about like an average east coast hunting rifle. Nothing to write home about.
If you really want a painless conversion of an Arisaka, try .300 Savage. Set the barrel back a little and recut the chamber. You will have some feeding issues too, but can overcome them. I have owned a couple I picked up at yard sales and shows. Good little shooters.
Wow. Just looked at this post. Time to lay off the coffee.
Jim Watson
New member
Wow, what a project. Almost as much work as putting a Mauser bolt in a Mannlicher action that I read about.
You have more guts than I, Gunga Din, I mean Gunplummer. I never would have thought of tackling that kind of project; I would just have sold the guy a new rifle.
Guys want to do that kind of thing when some cartridge or other is cheap and they think they will save money if they can just convert that old rifle to use the cheap ammo. But in the end, the work (if they find a gunsmith who will do it) will cost more than they could ever possibly save in ammo unless they have to fire a thousand rounds a day for a year. In practical terms, they could never fire enough to begin to amortize the conversion costs. And they ruin what might some day be a collectible rifle. (Those of us who hacked and chopped on Arisakas, Mausers, Springfields and Enfields get the shakes looking at today's prices!)
Jim
Guys want to do that kind of thing when some cartridge or other is cheap and they think they will save money if they can just convert that old rifle to use the cheap ammo. But in the end, the work (if they find a gunsmith who will do it) will cost more than they could ever possibly save in ammo unless they have to fire a thousand rounds a day for a year. In practical terms, they could never fire enough to begin to amortize the conversion costs. And they ruin what might some day be a collectible rifle. (Those of us who hacked and chopped on Arisakas, Mausers, Springfields and Enfields get the shakes looking at today's prices!)
Jim
Gunplummer
New member
Can't say I ever hacked on a complete military rifle I bought. Well, matching numbers anyway. Mismatched was fair game. There used to be plenty of guns around that were abused or missing wood. You can't even find cheap guns to repair anymore. People buy them and strip them for parts to sell on ebay and at shows.
Today, most gun folks get up tight about "sporterizing", but it once was common, and I did it. Convert K.98k's that would make a modern collector drool to 8mm-06 and drop them into a Fajen stock. Convert Type 99s to .30-'06 and Type 38s to 6.5-257 or rebarrel to .300 Savage or .257. Chop the ears off M1917s and grind the receiver bridge to a round shape (modern owners wonder why the "standard" scope mount base won't fit). Drill and tap M1903's and those awful hard '03A3s. Etc., etc.
The up side is that those of us who kept military rifles intact are now benefitting by selling off those $25 rifles for $500-800 or more. If people had left them alone, they would be common and not worth nearly as much.
Jim
The up side is that those of us who kept military rifles intact are now benefitting by selling off those $25 rifles for $500-800 or more. If people had left them alone, they would be common and not worth nearly as much.
Jim
Not without changing the barrel. The 7.62 x 54R case length is 178 thou shorter than the 7.7 Jap. And you're converting from rimless to rimmed with an odd rim shape.
Cheaper and less fuss(not to mention less stress for milsurp shooters/collectors) to buy 7.7 Jap ammo or brass.
Cheaper and less fuss(not to mention less stress for milsurp shooters/collectors) to buy 7.7 Jap ammo or brass.
with original brass being available and brass that can be reformed to, i would not rechamber any of my many milsurp rifles. 7.7 japanese can be made from 8x57 mauser just by resizing it in a 7.7 size die. example with 30-30 brass i make 25-35, 303 savage, 32-40, 32spl, 38-55 that allows me to shoot the rifles very cheaply. i buy all the brass i can at flea markets, yard sales and gunshows, i clean it, prep it, size it and store it in air tight containes. i load and shoot some weird calibers in older military and civilian rifles. to me its part of the fun owning old and odd ball calibers and getting them to spit fire and lead again. i also hunt with them. eastbank.
7.7 japanese can be made from 8x57 mauser just by resizing it in a 7.7 size die.
I had a friend that claimed he was going to get on a train in Amarillo, TX going to Tucumcari, NM. He claimed he ask them when the train left and when did it arrive. They informed him the train left at 9AM and arrived at 9:30AM. And then they asked him if he wanted a ticket and he said no but I do want to watch it take off.
That brings us to the 8mm57 to 7.7mm58, loosely translated there is 1mm difference in length, that is close to .040” difference, so like my friend I am going to back up and watch that one take off; but I am thinking there was something my friend did not understand about time zones or there was something the rail road did explain to him.
And then he decided he would go to the New Orleans Mardi Gras, he should have came with a warning label.
F. Guffey
the difference is in the lenth of the neck and does no effect base to shoulder lenth. and its shorter than the regular 7.7 neck lenth and has no effect on safety. i have plenty of factory 7.7 cases to use, but i have loaded the reformed 8mm to 7.7 in my t-99,s with no porblems at all(i don,t try to make a magums out of any regular rifles). i agree its better to use the right ammo in any rifle, but if cases are not normely available and you want to shoot the rifle you must improvise. the 8mm to 7.7 forming is alot easier than 3006 to 7.7 and as the base diameter of the 3006 and the 8mm are so close, its just as safe to use 8mm to 7.7. no train to watch or catch here. eastbank.
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I think Guffy is right. 8mm is shorter than 7.7 Jap by about 1mm, not only overall brass length, but also from head to shoulder datum. You probably will have excessive head clearance, at least for the first shot. The brass will fire form to the new chamber after that. There could still be a train to catch or miss at that station.
8mm brass can be expensive too. At least for me, there is no point doing 8mm to 7.7 Jap. Starting from 30-06 makes most sense, both technically and economically.
It makes even less sense to convert a t99 to shoot 7.62x54r.
-TL
8mm brass can be expensive too. At least for me, there is no point doing 8mm to 7.7 Jap. Starting from 30-06 makes most sense, both technically and economically.
It makes even less sense to convert a t99 to shoot 7.62x54r.
-TL
You probably will have excessive head clearance, at least for the first shot
And when the case forms to the chamber the case will get shorter; again, I have cases I form to wildcat chambers that shorten .045". to correct the problem I start with longer cases.
F. Guffey
as long as you have enough neck to grip and hold the bullet it will be ok. the neck has nothing to do with head space and the extractor will hold the case back against the bolt face during fire forming. i have a .223 ackley improved and you should see the short neck compared to a regular .223 after fire forming from regular .223,s. my main worry with 8mm to 7.7 is the same with the 3006 to 7.7, the base is smaller than the 7.7 and must be watched for case seperation. i formed 3006 to 7.7 and never had a head seperation, the same with the 8mm to 7.7. i have never heard of a problem with 3006 to 7.7 when reformed to make ammo for the 7.7 before the importation of norma for all the japanese rifles brought back for ww-2. since not many would pay the money to have the barrel set back on what most at that time thought was a junk rifle. eastbank.