Jap 7.7 Ammo...Safe to Shoot?

Arisaka, Murata, Siamese, Korean, and North China Rifles
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Jap 7.7 Ammo...Safe to Shoot?

Post by 728shooter »

Have a chance to buy some original military Jap 7.7 ammo, some loose, and some on 30-round charger strips. Was told that the ammo on the chargers was for MG's. No head stamp markings on any of it that I looked at, so no idea as to when it was made or where. My question is:

1) Is it safe to use any of this ammo in my Arisaka type 99?
2) Have heard that machine gun ammo was usually loaded for higher pressures. Have also heard that of all the major military WWII rifles produced, the Arisaka receiver was the strongest receiver ever made. Can individual MG rounds be used in the type 99?

Have a chance to buy this ammo for a lot cheaper than new stuff. All cases look exceptionally clean, minor tarnish but no corrosion. Someone suggested that the bullets be pulled and reload the cases with a correct (safe) charge; only problem is, I do not reload. Appreciate any and all thoughts on this.

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72 usmc
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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by 72 usmc »

I shoot only Norma 7.7 and it works fine but big bucks. See this video.
https://www.youtube.com/watch?v=Cy94JS0CJhQ

you see lots of cheep machine gun ammo nice for display: https://mg34.com/product/30-rds-of-7-7- ... ifle-ammo/
Screen Shot 2019-12-11 at 9.27.56 PM.png
Screen Shot 2019-12-11 at 9.27.56 PM.png (1.13 MiB) Viewed 2377 times
https://mg34.com/product/30-rds-7-7-jap ... le-ammo-2/ AP


Ans is no , just buy factory ammo or make some out of 30-06. My 2 cents.
An additional word on the subject, 7.7 x 58 machine gun ammo is semi-rimmed, but during the importation of ex-Chinese arms and equipment some enterprising characters either here or there began to take the ammo and turning it on a lathe and remove enough of the rim so that it would work on 99 rifles and light machine guns.
Then some users here in the states began to experience case head splits, failure to fire and so reported into Banzai as warning to others to avoid ammo with shinny case head and grooves.
So not only must you be aware to use only recent manufacture ammo with known components, but also be on guard on unknown - unmarked - bargain stuff.
If the ammo in question is original Type-92 ammo it will not feed onto a 99 rifle bolt head. I have seen one 99 bolt in which the bolt face was milled out enough to accept a semi-rimmed case head, in that case the bolt will pick the round from the magazine and chamber it.
Another consideration original rifle ammo fired a 183 grain bullet, while the T-92 was 203 grains with a larger powder charge as well. Add that to 60 + year old brass of dubious quality and hurried manufacture, removal of head material to rimless specs which includes cutting a deeper extractor groove. You can now see why case failures began to occur.
Now you know why such ammo is not such bargain.
Vicasoto
SOURCE https://forums.gunboards.com/showthread ... hot-Safely
The 7.7 ammo on feed trays is for the Type-92 HMG a Hotchkiss design machine gun, the cases are semi-rimmed. Type 99 rifle ammunition uses a rimless case, that should tell you that you cannot cycle semirimmed ammo in a rifle.
Note also that some enterprising importer took semirimmed ammo and had the case heads turned on a lathe down to and the extractor groove recut as well so that it would work on rifles, then purchasers began to experience ruptured cases and excessive recoil.
There has been little 7.7 rimless imported over the years, most being destroyed or dumped into Tokyo Bay. The Chinese did manufacture some but much was used up in Korea and afterwards. You can save your brass and reload, that is the least expensive way to enjoy shooting T-99 rifles and LMGs.
Another thing to keep in mind, rifle ammo originally used 182 gr. bullets whereas the T-92 HMG semirimmed ammo fired 203 gr. bullets. So even if you broke down the T-92 ammo for components the only thing you could use are the bullets.
Best to stick to safe and tried commercial ammo to start with and then reload.
Vicasoto
SOURCE https://forums.gunboards.com/showthread ... hot-Safely


AMMOLAB is the ammo expert here and he most likely will chime in :clap: :clap: :idea:
To old to fight and to old to run, a Jar head will just shoot and be done with you.

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by 728shooter »

72 usmc, thank you for that information. Looks like I'll pass on buying it, not worth the chance of messing something up!

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by slowbob2 »

Mr 72 usmc , your first video posted about the 7.7mm ammo is ok . He gets all the cartridge id's and uses correct , but he gets all the tech stuff wrong . The reason the heavy bullet MG 7.7 ammo was not used in the rifle was not the strength of the action , it was the recoil . The 7.7mm rifle ammo was underloaded some to reduce the felt recoil . Also the 7.7x58 round had nothing to do with the 303 brit , it was just a 8x57mm round necked down to 7.7mm because they were already making that size bullet . They were going to machine guns based on 8x57mm designs .

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by ammolab »

The semi rim just isn’t practical for rifle shooting. It is the rim not the “load”...pressures are not excessive in Japanese MG ammo.
The Type 92 will function with the rimless rifle 7.7x58 ammunition and some of the Chinese import ammo did have rimless 7.7 on the MG feed strips. I had MANY cases of the Jap Ammo when imported and opened quite a few to sell MG strips at the Texas gun shows. I saved several cases of rimless for my rifle. All of it shot, but primer gas leaks on 50% of the rounds cured me. Sold it all.
Not good mfg, not good storage, time wasn’t good to this ammo.

Regardless of the Rim type found, that ammo is collectible not shootable.

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by Tuna »

The only difference between the 7.7 rifle round and the 7.7 machinegun round was the semi rim for the machinegun round. The specs for the ammo was the same. Same powder charge, same bullets and velocities. Now if you want you can add in the third 7.7 round made for the British Lewis gun used by the Japanese navy. Yes its the same round as the .303 British standard. It was a quartermasters nightmare trying to get things straight. I know of one supply officer who was stationed on an island about 25 miles north of Iwo Jima. He would order ammo for rifles and would get ammo for machineguns including the .303 meant for the navy. He said it was a mess tying to get what he needed out of H.Q. ammo wise.

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by slowbob2 »

No the ammo was not the same . Different bullet ,different velocities . It is not a secret , it is documented and you can look at real ammo .

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Re: Jap 7.7 Ammo...Safe to Shoot?

Post by ammolab »

slowbob2 wrote:
Thu Dec 12, 2019 4:44 pm
No the ammo was not the same . Different bullet ,different velocities . It is not a secret , it is documented and you can look at real ammo .
Yes, not the same...heavier ball bullet in the semi-rim MG ammo. But not loaded to “hot MG” pressure levels. “MG Ammo” that IS NOT suitable for a rifle so chambered is a very rare item, VERY rare!

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