Allin Conversion
Springfield Armory (US Government) · Rifle · Discontinued · 1866
Also known as: Springfield Model 1866, Second Allin Conversion, Trapdoor Springfield (1866)
Overview
The Allin Conversion is a single-shot, breech-loading rifle developed at the U.S. Springfield Armory by Master Armorer Erskine S. Allin. Officially the Springfield Model 1866 (the Second Allin Conversion), it was created by milling out the breech of surplus Civil War muzzle-loading rifle-muskets and fitting a hinged 'trapdoor' breechblock, converting them to fire the metallic centerfire .50-70 Government cartridge. The design gave U.S. troops a rapid, reliable breechloader and established the trapdoor mechanism that would define American service rifles into the 1870s and 1880s.
Specifications
| Weight (empty) | 4170 g (147.1 oz) |
| Overall Length | 1400 mm (55.12") |
| Barrel Length | 1020 mm (40.16") |
| Action Type | Trapdoor |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Action |
| Magazine Capacity | 1 rounds |
| Magazine Type | None |
| Muzzle Velocity | 381 m/s (1250 fps) |
| Muzzle Energy | 2120 J (1564 ft·lbf) |
| Effective Range | 300 m (328 yd) |
| Maximum Range | 900 m (984 yd) |
| Rate of Fire | 10 rpm |
| Barrel Rifling | Right Hand |
| Number of Grooves | 3 |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Walnut |
| Finish | Blued |
Calibers
- .50-70 Government · primary — also known as .50-70 Musket, .50-70-450
Features
- Firing modes: Manual
- Feed systems: Single Shot Breech Loading
- Safety mechanisms: Half Cock Notch
- Features: Hinged Trapdoor Breechblock, Converted Muzzleloader, Open Sights
Service history
Operators
- United States Army · adopted 1866 · as Model 1866
- French Army · adopted 1870
Conflicts
- American Indian Wars (1867-1868)
- Franco-Prussian War (1870-1871)
Production
Estimated total produced: 52,000 · Production years: 1866-1868
Approximately 52,000 produced under Allin's supervision at Springfield Armory; a large share were sold to France during the Franco-Prussian War, the remainder issued to U.S. troops.
Origin
Country of origin: United States
Designer: Erskine S. Allin
Discontinued: 1868
Notes
The 1866 'Second Allin Conversion' chambered the .50-70 Government cartridge, replacing the ineffective .58 rimfire of the earlier 1865 'First Allin Conversion'. It proved decisive at the Wagon Box Fight and Hayfield Fight (1867) along the Bozeman Trail.
Background
Erskine S. Allin's conversion was prized as 'pure Yankee ingenuity', a cheap way to turn a mountain of obsolete Civil War muzzleloaders into modern breechloaders. At the 1867 Wagon Box Fight, soldiers armed with the new .50-70 trapdoors held off a far larger Sioux and Cheyenne force whose warriors expected the slow reload of muzzleloaders.