Korean War Type 99

[Oxmix]

I have a type 99 that was rechambered to 30.06 during the Korean war and distributed to the KATUSA's. Any one have any information on them, such as how many were converted.

A friend bought a whole crate of them. I bought the last one she had.

Regards

Ox

Information

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[Jim K]

Honeycutt says some 6650 Type 99 "long" rifles and some 126,350 "short" rifles were converted, for a total of 133,000. They were converted simply by rechambering them with a .30-'06 reamer and then lengthening the magazine and notching the receiver. They were not rebarrelled, so the bullet was slightly too small (.308" vs .311") for the barrel. I have seen one but never owned one and so can't say how well they shoot. (I guess, considering the situation, that "minute of North Korean" was good enough.)

Whether they were ever used in combat, though, seems to be in question. They may have been issued to the Korean Constabulary, in which case probably any weapon would have been adequate. I may be wrong, but I thought the KATUSA's were mainly translators and liason to the population; since they were "embedded" in the US Army, I would think they would have American weapons.

The conversion, BTW, is entirely safe; not only is the Type 99 quite strong, but the bullet is undersize, so pressure will be low.

I hope you will opt to fire yours some and let us know how well it shoots. The same condition could be created by necking 7.7 down to .30 and firing it in a Type 99, but it would be more interesting to actually fire one of those conversions.

Jim

[RCS]

Hatcher points out in his notebook (page 210) that on converted Japanese rifles that are rechambered to shoot our 30-06 cartridge, the chamber is still too large in the rear, inviting the case to split. If the 30-06 brass is perfect without any flaws, the chance is slight, but will happen more easily then it will in a tight chambered rifle such as the Model 1903.

[mike radford]

I have one and have shot it. It is minute of man accurate at 100 yds and definitely not a tack driver. Seems like the groups were about 12 inches. It shot very high. Mine was built on a series 9 Howa. Seems like an earlier rifle would have been a better choice.

[Jim K]

I have been reading for years that the .30 is too small at the base for a 7.7 chamber, and at one time I pretty well accepted it, but it seems to be more in theory than in practice. COTW gives the base diameter of the .30-'06 as .470" and that of the 7.7 as .472", both well within each other's tolerance range, and .002" difference is within the cartridge/chamber tolerance of just about any cartridge made.

I have seen plenty of 7.7 rifles that were converted to .30-'06 by gunsmiths, and none ever split cases. I have also fired 7.7 cartridges in unaltered .30-'06 chambers with none of the supposed dire results, except a short case neck. There were no signs of high pressure, not even flat primers. (This seems to have been one of those WWII ammo swap stories that is plausible and may even be true - unlike similar stories of German 8mm/.30 rifles and ammo.)

Maybe if the .30 base were on the small side and the 7.7 chamber on the large, there could be a problem, but I am inclined to think that what we have here is one more gun myth, and I suspect that Hatcher accepted it without really checking, unusual for him.

Jim

[Calif-Steve]

When I was a young man growing up in Hawaii I knew of several Type 99's in .30-'06. This was a very popular conversion done in the Islands. I never heard of any problems, either. I knew a Hawiian gentleman who had been an intrepreter in the US Army. He actually helped dis-arm the Imperial Palace Guards and had the Type 99 still at home from a Guard.

[Jim K]

The conversion of the Type 99 to .30-'06 was one of the most common gunsmith jobs in the post-war years. There must have been hundreds of thousands of them done, and I never heard of a problem because of the chamber diameter. (Less than great accuracy was another issue, but most would hit "minute of deer" at hunting distances.)

The American Rifleman reported one case where the owner of a Japanese rifle decided to do the conversion himself. His rifle, though, was not a Type 99 but a Type 38, 6.5 caliber. The guy ground down the reamer pilot and fired .30-'06 in the rifle. He wrote the NRA to ask what he could do about the noise and blast. When he told them what he had done, they bought the rifle from him to experiment. The article showed some of the fired bullets - talk about a loooonnnng bullet! Pretty much put paid to the idea that the Arisaka action was weak.

Jim

[cary m2a]

I do recall .30-06 brass being resized to be used in 7.7Jap when I was a kid.Like now hard to find the right stuff or just cost to much. I dont think they had any split cases.

Cary

[sigman2]

I just fired some reformed 30/06 this past Sunday. All functioned fine and accuracy was good. There was a slight case bulging just in front of the case head. I'm sure there was a considerable variation in the Jap chamber dimensions. ine may be on the large side.

[andiarisaka]

What Hatcher was referring to is what "could" happen if one was to experience a longitudinal split in the rear of case body. This was common with some FA34 brass, and I've used some 1950's Israeli .308 brass that had this problem (not in the type 99). As of 1947, hatcher had only seen one case of it with the 7.7, though he didn't say what year or manufacturer case it was. The difference in case head size is really no more than that of US vs European manufactured 6.5x55, where US made is some .008" smaller.