Springfield Armory National Historic Site - Erskine S. Allin, Genius of Springfield Armory (U.S. National Park Service)

Erskine S. Allin, Inventor and Genius of Springfield Armory, modified the breech of the standard rifle-muskets to create the breechloading Trapdoor.

Springfield Armory NHS Archives

Erskine S. Allin created the breechloader .45-70 Trapdoor by redesigning the breech of the standard rifle-musket.

Erskine Seleuca Allin (1809-1879)

In 1865, Master Armorer Erskine Allin introduced the "Allin Conversion", which incorporated the far more advanced design of breech-loading into the now-obsolete muzzle-loaders, thereby extending their service life.

Allin’s positions at Springfield Armory from 1829 to 1879, as recorded in his own hand written Recapitulation dated May 1, 1873: Mechanic – 11 10/12 years; Clerk – 1 1/12 years; Foreman – 5 9/12 years; Acting Master Armorer – 5 11/12 years; Master Armorer – 25 6/12 years; Acting Superintendent – 7/12 years. Promoted to Master Armorer – 1853. Total time at Springfield Armory: 50 years.

Accomplishments at Springfield Armory: “During the period I was Foreman, as well as after, I made some valuable improvements and suggestions in machining & tools, among which are the small tilt hammers driven by belts, and which are used up to the present time, the change in the method of case hardening, change for simp0lifying rifling machine, change in Colt’s drop hammer, and various other changes and improvements to simplify and reduce the cost of manufacture. I might perhaps state that the breech loading gun, the leading principle of which is my own innovation, I assigned to the government without royalty or pecuniary benefit; [its] standing after the trial, one of the best for the Military Service.”

His father, Obediah, was hired at the Armory in 1810 and obtained the position of Foreman which he held for 25 years.

courtesy: Al Frasca (www.trapdoorcollector.com)

The US Model 1865 Rifle was Springfield Armory's first breechloading rifle, first manufactured just after the Civil War in 1865. Know since as the "First Allin Conversion", it recycled many older Civil War-period muzzleloading parts. Firing a .58" caliber metallic cartridge, it was superceded in 1866 with an improved .50" caliber variant and, finally, starting in 1873 with a model in .45" caliber. Such rifles were nick-named "Trapdoor" rifles. In the hands of US Army soldiers duirng the wars with the Native Americans for control of the American West, they saw extensive use in many battles and, notably, in 1876 at Little Big Horn, Montana, in the hands of the US 7th Cavalry.