Cartridge of the Week, the 45-70 Goverment, 45-70-330, 45-70-350, 45-70-405, 45-70-500

By CTD Allen published on in Ammunition, Firearms

This week we go really old school with a big hoss, the 45-70 Government. This comes from a time when people not only rode horses, but also fired guns while riding them. This is among the largest cartridges we have examined so far. This cartridge’s energy exceeds that that of the venerable 30-06 Springfield from last week.

19th Century 45-70 Government Cartridges

Due to changes over time, we have to define this cartridge in two different eras. While developers conceived it during the black powder era, it managed to make the transition from black powder to early smokeless powder, and finally to modern smokeless powder.

The numbers of the cartridge defined the bullet diameter (.45), the mass of powder in grains (70), and the bullet weight in grains (330, 350, 405, and 500). However, the powder ratings are those of black powder or early smokeless powder. Modern powder loads range from 50.4-54.0 grains of modern smokeless powder.

1873 Springfield Trapdoor

The cartridge came about to compliment the new 1873 Springfield Trapdoor rifle used by the U.S. military. This rifle became both famous and infamous during the Indian wars which following the U.S. Civil War. Most infamously, the rifle was at Little Big Horn in June 1876 in the hands of the U.S. Cavalry. However, it was not the 45-70 cartridge that was partly responsible for the lopsided defeat of the U.S. soldiers that day. The cartridge used at the battle was the 45-55. Bean counters, in their infinite wisdom, believed the less powder would save barrels for longer use. Furthermore, armed with better repeating lever-action rifles, the Indians had the tactical and numerical advantage.

The Trapdoor is a single shot rifle that must be reloaded after each shot. The bean counters and brain trust of the military believed the soldiers would waste ammo with a repeating rifle, and the single shot would force them to take better aim at their targets.

The 45-70 cartridge still vindicated itself and returned to service following the Little Big Horn debacle. The 45-55 died along with the soldiers on that Montana hillside. However, the 45-70 survived, and it became a hunting caliber for taking game such as buffalo and elk. To this day, with the energy of 3500–3700 ft-lbs, it still is a big game threat.

Modern 45-70 Goverment

While this cartridge possesses true knockdown power, its greatest weakness is its trajectory in traditional firearms. The large hunk of lead falls to the ground quickly beyond 150 yards and accuracy is wanting at that distance or beyond. To get more distance out of this cartridge, you would need an increase in powder, and that would not have been good for most of the early 45-70 rifles. Only modern rifles have the durability to withstand the needed increase in pressure created from a larger amount of powder.

Modern guns with modern 45-70 ammunition can shoot consistently to about 200-250 yards. This would be a decent choice for larger game. I would be very leery of shooting modern smokeless powder ammunition in a 19th century rifle. I am sure there are those who will decry me for saying that, but if it were my gun and my head, I would protect them well and by a modern firearm. There are some things you can’t replace.

 

45-70 Goverment Ballistic Comparison
Cartridge  Bullet Weight Muzzle Velocity Muzzle Energy
30-30 Win 150 Grains 2,480 fps 2,049 ft.-lbs.
.303 British 150 Grains 2,690 fps 2,400 ft.-lbs.
45-70 Goverment 300 Grains 2,191 fps. 3,730 ft.-lbs.
7.62X51 /.308W 150 Grains 2,750 fps 2,518 ft.-lbs.
7.62X63 / 30.06R 150 Grains 2,900 fps 2,820 ft.-lbs.

 

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