The 6.5x50 Arisaka (6.5mm Japanese)
By Chuck Hawks
The 6.5x50 had a long run as a military cartridge. Introduced in 1897, it was to serve the Japanese Empire through two World Wars, right up until the Empire surrendered to the Allies in 1945.
The 6.5x50 military load consisted of a 139 grain FMJ bullet at a muzzle velocity (MV) of 2500 fps with about 1940 ft. lbs. of muzzle energy (ME). Presumably this velocity was measured in the 32" barrel of the Arisaka rifle. The 6.5x50 turned out to be an excellent battle cartridge; flat shooting with mild recoil, it was easy to shoot accurately.
The Norma factory load for the 6.5x50 drives a 156 grain Alaska bullet at a MV of 2067 fps with ME of 1480 ft. lbs. At 200 yards the figures are 1615 fps and 904 ft. lbs. For deer hunting, the effective range of this load is limited by its modest energy to about 200 yards. Norma trajectory figures are as follows: +4.4" at 100 yards, 0 at 200 yards, and -17.8" at 300 yards. Norma brass is Boxer primed and excellent for reloading.
The reloader can significantly increase the effectiveness of the 6.5x50. The 156 grain bullet is really too heavy for the capacity of the cartridge. The 6.5x50 case is a small, semi-rimmed bottleneck case with a 20 degree shoulder. The overall case length is 50mm (2"), and the COL is 2.992". It is a case of modest capacity, but takes standard 6.5mm (.264") bullets.
The 6.5x50 is at its best with medium weight (120-140 grain) bullets and medium burning rate powders. H335, H380, H4895, IMR 4064, IMR 4320, IMR 4350, and IMR 4895 are suitable powders.
The 26th edition of the Hodgdon Data Manual shows the following loads with 120 grain bullets (SD .246): 38.0 grains of H380 powder gave a MV of 2424 fps, and 41.0 grains of H380 gave a MV of 2595 fps. At 2500 fps a bullet of this weight starts with a ME of 1665 ft. lbs. These Hodgdon loads used standard large rifle primers and were tested in a 32" rifle barrel.
Using the 120 grain Nosler Ballistic Tip bullet as an example, the trajectory of this bullet at 2500 fps would be: +2.5" at 100 yards, 0 at 200 yards, and -10.1" at 300 yards. This would make a good 250 yard deer and antelope load.
The Hornady Handbook of Cartridge Reloading, Sixth Edition shows that 35.0 grains of IMR 4350 can drive their 129 grain bullets (SD .264) at a MV of 2300 fps. A maximum load of 39.6 grains of IMR 4350 can drive that bullet to a MV of 2700 fps. The ME at 2600 fps is 1937 ft. lbs. and at 300 yards the remaining energy is 1139 ft. lbs. Hornady trajectory figures for this load using the Spire Point bullet are as follows: +2.4" at 100 yards, 0 at 200 yards, and -9.7" at 300 yards. This would seem to be an excellent all-around 250 yard hunting load for North American deer, antelope, black bear, and similar size animals the world over.
The Hornady Handbook also shows that their 140 grain bullets (SD .287) can be driven to a MV of 2300 fps by 35.0 grains of IMR 4350, or to a MV of 2600 fps by a maximum charge of 39.2 grains of the same powder. The ME of the Spire Point bullet at 2500 fps is 1943 ft. lbs. and at 300 yards it is still carrying 1174 ft. lbs. of energy. The trajectory of that bullet looks like this: +2.7" at 100 yards, 0 at 200 yards, and -10.3" at 300 yards. These Hornady loads were developed using Norma brass and Federal 210 primers, and were tested in the 32" barrel of a Type 38 Arisaka rifle.
Note: A full length article about the 6.5x50 can be found on the Rifle Cartridge Page.
Copyright 2004, 2013 by Chuck Hawks. All rights reserved.