Springfield Model 1866
Springfield Model 1866
Country of origin



Springfield Armory


Erskine S. Allin

Weapon type

Breechloading Rifle


.50-70 Government


Hinged breechblock

Overall length

56in (1.42m)

Barrel length

36in (0.91m)


9lb (4.1kg)

Magazine/Cylinder capacity


Used by

US Army

The Springfield Model 1866 was a developed version of the Erskine S. Allin designed Springfield Model 1865 breechloading rifle. The major difference between the "First Allin" (Model 1865) and the "Second Allin" (Model 1866) was a simplified breechblock and ejector system.

Design DetailsEdit

The Springfield Model 1866 used a reinforced version of the 'Trapdoor' breechblock that Allin designed for the Model 1865. The Model 1866 used a stronger hinge to open and close the breech, with stronger springs which were less prone to failure. This design replaced the Model 1865 as the standard conversion for older percussion lock Springfields, such as the Model 1842 or Model 1855

The Springfield Model 1866 was also equipped with a modified extractor mechanism, to extract the new .50-70 Government cartridge, around which the Model 1866 was designed. The Model 1865 had used a rack system, which moved with the breechblock. The Model 1866, however, used a refined version of the extractor, using springs to make the removal of the cartridge quicker and easier.

However the Model 1866 still had problems when it came to reliability. Parts such as the extractor springs were prone to failure as was the 'trapdoor' system, both of which meant the Model 1866 obtained a reputation of being unreliable and the belief that the failure of the extractor springs disabled the Model 1866. This, however, could be avoided, as the springs were "convenient rather than necessary" therefore the Model 1866 could still be used, with the extractor hook still used to pull up the cartridge, allowing the user to flick out the cartridge by hand or using the ramrod, located under the barrel.

Springfield Model 1865

The Springfield Model 1865, the first of the 'Trapdoor Springfields'

The barrel was given 3 internal twists, with a ratio of 1:42 to spin the bullet more efficentely and improve the accuracy and stability of the bullet. The barrel was also relined (if an older Springfield was converted) to reduce the caliber from .58in to .50-70 Government round.


.50-70 Government cartridge

The new .50-70 Government cartridge used in the Springfield Model 1866

The Springfield Model 1866 was the first Springfield to use the Government issued, .50-70 cartridge. This contained a .50in (12.7mm) lead bullet with 70 grains of blackpowder enclosed in a metallic case. This proved to be a significant improvement on the older .58in (14.7mm) Minie Ball used with the Springfield Model 1865 and older Springfields.


The standard Springfield Model 1866 was modified to improve its role capabilities. The growing popularity of "Cadet" style rifles (scale models of a rifle, with all features (except the caliber) scaled down for training cadets and young trainees), along with the common developement of a short rifle version for any rifle, were the main drives behind the development of the Model 1866. 

Model 1866 Short RifleEdit

The Model 1866 Short Rifle was produced from 1870 until 1871, almost by accident, during the movement to refurbish over 20,000 Model 1866s for resale in Europe (during the Franco-Prussian War). The refurbishers came across some 1,500 Model 1866s that had been fired with a partial blockage, damaging the barrel and end of the stock. These rifles were shortened by 4in and the stock replaced (by the Type I Model 1863 stock, specifically shortened) before being sold on.

Model 1866 Cadet RifleEdit

A short production version of the Model 1866, with 424 examples built. These rifles had all parts, except the caliber, scaled down therefore making the Model 1866 Cadet very delicate. The small scale normally meant that the wooden stock would snap during training. Furthermore the front sight was only soldered on, due to the barrel being thinner, which meant it would often be snapped off. 


The Springfield Model 1866, like the Model 1865, was issued to US troops a year after its initial release. It was not, however, issued across the entire United States forces, and it was up to the individual soldier to convert their older percussion rifle or rifled musket to the Model 1866. The Model 1866 would also be improved upon by the Springfield Model 1868, while also forming the basis for the Springfield Model 1873, the first breechloading rifle to be produced by the American government, as well as Springfield. 

The Model 1866 remained, technically a Percussion rifle, using the percussion lock system to ignite the cartridge. However it was also recognised, at the time, as a rifled musket in service manuals. This was most likely due to the length of the barrel, which at the time was used to define a musket. Around 52,000 examples were built or converted from older Springfields.

Dreyse Needle gun

The Dreyse Needle gun of Prussia, originally designed in the 1840s.

In Europe at the time, contrary to the plans of Springfield to refurbish and sell the Model 1866 in Europe, the breechloading rifle had been in use for some time, although not on a wide scale. The Norwegian Kammerlader rifle and Prussian Dreyse Needle gun had been used since the 1840s and the French had developed the Chassepot rifle by the start of the Franco-Prussian War. The Model 1866 never had an impact on the European arms market, leading to most examples being scrapped or sold to civilians, with other nations, such as Britain, already recognising the need for breechloading rifles (as early as the 1770's when the Ferguson rifle was first manufactued). Furthermore the Model 1866 was not the first breechloading rifle to exist in American military circles, the M1819 Hall rifle claimed that honor (although it was not used in great numbers).

ResourcesEdit - .50-70 Government Cartridge image

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