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. As far as I know, however, it was never adapted to sporting rifles in all that time.
In 1905 the Arisaka Model 38 bolt action rifle was adopted for the 6.5x50 cartridge. The Arisaka is an ungainly looking but very safe modified Mauser bolt action rifle of great strength. I have read that during testing to destruction after the end of WW II the Arisaka Model 99 (a modified design in 7.7x58mm) survived pressures that destroyed all of the other famous bolt action rifles of WW II, including the American 1903 Springfield and German Mauser Model 98 rifles. Not many Westerners realize that the Japanese Arisaka service rifle of WW II was the strongest military bolt action rifle ever produced.
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.
Victorious Allied soldiers brought the first Arisaka rifles home as war trophies. But in the 1950's, surplus 6.5x50 Arisaka rifles arrived in the US in numbers. Norma of Sweden eventually offered factory loaded ammunition and brass in 6.5x50, and Arisaka rifles began to be used in North America as inexpensive knockabout hunting rifles. American hunters soon discovered that the commercial version of the 6.5x50 cartridge killed medium size big game very well--something that their European allies, long used to effective cartridges like the 6.5x54 and 6.5x55, could have told them in advance.
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.
That is a good thing, as the reloader can (in my opinion) 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. It has a rim diameter of .466" and a body diameter at the base of the case of .447". The overall case length is 50mm (2"). It is a case of modest capacity, smaller in fact than the 6.5x52 Italian or 6.5x54 Mannlicher-Schoenauer in all dimensions, but takes standard 6.5mm (.264") bullets.
It is therefore at its best with light to medium weight bullets for the caliber, not the heaviest, and medium burning rate powders. 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 spitzer bullet of this weight starts with a ME of 1665 ft. lbs. and at 300 yards the kinetic energy is still 1031 ft. lbs. Using the 120 grain Nosler Ballistic Tip bullet as an example, the trajectory of this load would be: +2.5" at 100 yards, 0 at 200 yards, and -10.1" at 300 yards. This makes a good 250 yard deer and antelope load, limited this time by its trajectory, not its energy.
The Hornady Handbook, Third Edition shows loads using 35.2 grains of IMR 4320 or 38.5 grains of IMR 4350 and their 129 grain Spire Point bullet (SD .264) at a MV of 2600 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 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 Spire Point bullet (SD .287) can be driven to a MV of 2500 fps with 37.8 grains of IMR 4350 or 33.5 grains of H4895. The ME of this bullet at 2500 fps is 1943 ft. lbs. and at 300 yards it is still carrying 1174 ft. lbs. of energy. The trajectory of this deep penetrating bullet looks like this: +2.7" at 100 yards, 0 at 200 yards, and -10.3" at 300 yards.
A 140 grain bullet would probably be the optimum load for larger game such as North American caribou, European red stag, or many of the larger African antelope species if you had to use a 6.5x50 rifle for the purpose. If you get the bullet into the right place it should do the job. One thing for sure, if you have an Arisaka M-99 rifle in sound condition you can use near maximum loads without concern for its safety. This (plus that long 32" barrel) lets the little 6.5x50 out perform the larger 6.5x54 cartridge, and fall not too far behind the performance of the famous 6.5x55.
Copyright 2002, 2012 by Chuck Hawks. All rights reserved.