The Trapdoor rifle design is not one you hear about often. It was a breach-loading stopgap between the end of the muzzleloading era and the emergence of bolt actions. Most of the world went straight to the bolt action. Prussia adopted the bolt action Needle gun as early 1841 and in 1866 France adopted the  Chassepot bolt action. Even the US Army was all set to go the bolt action route when they adopted a limited number of Palmer carbines, but after the War Department had its budget slashed following the end of the Civil War, they cut firearms expenditure (who says history does not repeat itself?).

RIA have published a fascinating article on the history of the Trapdoor rifle …

After the Civil War, the War Department wanted a breech-loading rifle.  To be specific, they wanted a breech-loading rifle that would chamber a self-primed, metallic cartridge.  This led to the formation of an Army Board who, in 1865, would host trials of different rifles by makers both foreign and domestic.  The idea of the Master Armorer at the U.S Armory at Springfield, Mr. Erskine S. Allin, was to take the existing Civil War muzzle-loaders, of which there were thousands, and convert them by adding the now well known “trap door” to the receiver.

This appealed to the Board for a number of reasons:

1. It used existing materials, thereby saving money and manufacturing time.
2. Money was even more important with the War Department’s newly slashed budget.
3. Single shots were viewed as more reliable and rugged than repeaters or magazine rifles.
4. It looked like proven guns of the past, especially with its pronounced hammer.
5. Their priority on long range accuracy over rate of fire.
6. Single shot rifles were thought to force a more efficient use of ammunition

If you wonder where the Trapdoor got its name from, take a look at the nifty gif animation below (it may take some time to load) …