The .45-70 Government (11.6×53.5mmR) is a rifle cartridge which was originally developed alongside the Springfield Model 1873, one of the various "Trapdoor" Springfield Rifles. In full it was called the .45-70-405 (meaning it was .45 inch caliber, with a 70 grain black powder load and a 405 grain bullet). It replaced the .50-70 Government cartridge, which had been in use for 7 years, and remained in use until the Springfield M1903 was introduced 30 years later, although the .45-70 remains in use to this day in sporting environments.
The .45-70 was manufactured with a brass case which was rimmed and given a very slight taper as it was thought, at the time, that this feature would work better with the breech mechanism. The original bullet used with the .45-70 was .458 caliber and weighed 405 gr (hence the official name .45-70-405) although this was changed to a 500 gr bullet after various trials. Both of these bullets were made of lead and would deform slightly to engage with the rifling in the barrel, and both measured .458in (11.6mm) in diameter.
The original 405 gr bullet with a standard .45-70 cartridge would achieve a muzzle velocity of 1,394 ft/s (425 m/s) and was expected to create a group no larger than 4in (100mm) at 100 yds (91m). In 1879 a heavier 500 gr bullet was tested, performing significantly better than the original in terms of ballistics, shown to be capable of achieving much greater distances (over 3,500 yds), although it was still no more accurate against a single target than the original bullet was.
Once the .45-70 became more of a commercial cartridge in the 20th century various 300 gr bullet types became available. The first of these, still retaining the use of blackpowder as the main source of propulsion, would achieve a muzzle velocity of 1,597 ft/s (487 m/s) and produce 1,700 ft lbf (2,304J) of energy. Later, JHP bullet types were produced for the .45-70, distinguished between "Strong" and "Standard". The "Strong" version of the JHP bullet produced a muzzle velocity of 2,275 ft/s (693 m/s) while the "Standard" produced a muzzle velocity of 2,070 ft/s (631 m/s).
The .45-70 Government rose to prominence in the late 1800's, as the Springfield Armory decided to focus on producing breech loading firearms, named the "Trapdoor" Springfields. Originally the Springfield Model 1866 was chambered to fire the .50-70 Government cartridge (the predecessor to the .45-70) although this was quickly changed as Springfield and the US Government realised that a smaller calibre would be just as effective.
The .45-70 Government was the result of this discovery. Developed alongside the Springfield Model 1873, the .45-70 was more effective than its predecessor as well as being more efficent. Over time the .45-70 was modified, as were the "Trapdoor" Springfields (eg the Springfield Model 1884), and served as the main ammunition of the US Military (both army and navy) up until 1893 (although official navy use extended to 1897).
The mass movement towards smokeless powders at the end of the 19th century spelt the end of the blackpowder .45-70 as the main ammunition of the US Military, although several firearms continued to use it. Overtime the .45-70 firearms were gradually swept from US Armories, becoming purely hunting and sporting firearms in the 20th and 21st centuries. Nonetheless the .45-70 has remained a popular round, being retained as a training cartridge and as the cartridge for line throwing guns used by the US navy.
The .45-70 Government, by virtue of having been developed by the US Government, was originally produced the the US Government run Springfield Armory, as well as several other contracted gunsmiths. Overtime the number of producers waned down to a limited few, with the most widely known producer of the .45-70 at present being Hornday.
.45-70 FirearmsVarious firearms have utilised the .45-70 Government since its initial enlistment. These firearms include:
- Springfield Model 1873
- Model 1879 Lee Magazine Navy Contract Rifle
- Springfield Model 1884
- Model 1885 Remington-Lee Magazine Military Rifle
- Marlin Model 1895SBL
- Magnum Research BFR
- Ruger No. 1 Rifle
Other firearms are capable of chambering the .45-70, indeed several older Springfield rifles were re-configured to accept it. However those firearms that have had a conversion to accept the .45-70 are not generally as efficient as those that were designed to use it, much like any other cartridge.