Japan's WWII-era upgrade from the 6.5mm Arisaka — a full-power rifle cartridge developed after combat experience in China showed the 6.5mm was marginal at extended range. The Type 99 Arisaka rifle chambered for it is considered one of the strongest bolt-actions of WWII.
Type: Rifle
Introduced: 1939, Japan
Parent case: None
Standardization: None
Bullet diameter: 0.311" (7.9 mm)
Case length: 2.276" (57.81 mm)
Overall length: 3.07" (77.98 mm)
Max pressure: 50,000 PSI
Rim type: Semi-Rimmed
Primer: Large Rifle
Typical twist rate: 1:10
Muzzle velocity: 2400–2500 fps
Muzzle energy: 2230–2494 ft-lbs
Effective range: 600 yd
Common bullet weights: 174, 180 gr
Primary use: Military
Production status: Discontinued
Also known as: 7.7mm Arisaka · 7.7mm Type 99 · 7.7mm Semi-Rimless · 7.7x58mm Arisaka
History: Developed in 1939 as Japan recognized the 6.5x50mm Arisaka was being outranged by Chinese .30-caliber rifles. Adopted for the Type 99 rifle and Type 99 LMG. Japan entered WWII with two standard rifle cartridges — the 6.5mm and 7.7mm — creating logistics complications. Both were used throughout the Pacific War. The Type 99 action was exceptionally strong; many survive in shootable condition.…
Notable firearms: Type 99 Arisaka, Type 99 Light Machine Gun, Type 92 Heavy Machine Gun
Military use: Japan
Similar cartridges: 7.92x57mm Mauser, .303 British, .30-06 Springfield