In firearms, a trapdoor is a form of breech-loading mechanism for

rifle A rifle is a long-barreled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves ( rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with ...

s in which a hinged

breechblock A breechblock (or breech block) is the part of the firearm action that closes the breech of a breech loading weapon (whether small arms or artillery) before or at the moment of firing. It seals the breech and contains the pressure generated by t ...

rotates up and forward, resembling the movement of a trapdoor. The Springfield models

1865 Events January–March * January 4 – The New York Stock Exchange opens its first permanent headquarters at 10-12 Broad near Wall Street, in New York City. * January 13 – American Civil War : Second Battle of Fort Fisher ...

and 1873 were best known for first employing this type of action.

Specifications

The ''trapdoor'' ''mechanism'' employed a hinged

that rotated up and forward, resembling the movement of a trapdoor, to open the breech of the rifle and permit insertion of a cartridge. The hinged breechblock caused these rifles to be named "Trapdoor Springfields". The conversion from musket to breechloader was done by milling open the barrel's breech section and inserting a hinged ''trapdoor'' fastened to the top of the barrel. A thumb-operated cam latch at the rear of the breechblock held it shut when in closed position. The rack-type system extractor was withdrawn automatically as the breechblock was opened and snapped back at the end of its stroke. The firing pin was housed within the breechblock. The hammer nose was flattened to accommodate the firing pin. Approximately 5,000 Civil War Model 1861 rifled muskets were converted at the Springfield Armory in 1866. It soon became apparent that many of the small working parts in the breech system were not going to have a long service life, and the action was too complicated for normal service use. Therefore, before the Model 1865 production order was completed, a less complex rifle was already being tested. This caused the Model 1865 to be called the "First Allin", and the following revised model, the

Springfield Model 1866 The Springfield Model 1866 was the second iteration of the Allin-designed trapdoor breech-loading mechanism. Originally developed as a means of converting rifle muskets to breechloaders, the Allin modification ultimately became the basis for t ...

, to be called the "Second Allin". The Springfield model 1865 fired a rimfire .58-60-500 cartridge (.58 inch bullet, of black powder), the caliber matching that of the Civil War Minié ball, which was originally used in these rifles. The Model 1865 quickly became obsolete, and most of them were sold in the 1870s to several American arms dealers. At the time, there was a large demand in the US for shorter cadet-style rifles. To satisfy this need, these dealers cut the barrels and stocks to make short rifles with 33-inch and 36-inch barrel lengths. Likewise, the stock wrists were often thinned for cadet use.

Selection process

In 1872–1873 a military board, headed by Brigadier-General

Alfred H. Terry Alfred Howe Terry (November 10, 1827 – December 16, 1890) was a Union general in the American Civil War and the military commander of the Dakota Territory from 1866 to 1869, and again from 1872 to 1886. In 1865, Terry led Union troops to vi ...

, conducted an examination and trial of 99 rifles from several domestic and foreign manufacturers, including those from Springfield, Sharps, Peabody, Whitney, Spencer, Remington, and

Winchester Winchester is a City status in the United Kingdom, cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government Districts of England, district, at the western end of the South Downs Nation ...

pursuant to the selection of a breech-loading system for rifles and carbines for the U.S. Military. The trials included tests for: accuracy, dependability,

rate of fire Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. This can be influenced by several factors, including operator training level, mechanical limitations, ammunition availability, and weapon condition. In m ...

, and ability to withstand adverse conditions. Both single-shot and

magazine A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...

-equipped systems were considered, but, at the time, the single-shot was deemed to be more reliable. Firing tests were held at the

Springfield Armory The Springfield Armory, more formally known as the United States Armory and Arsenal at Springfield located in the city of Springfield, Massachusetts, was the primary center for the manufacture of United States military firearms from 1777 until ...

and

Governor's Island Governors Island is a island in New York Harbor, within the New York City borough of Manhattan. It is located approximately south of Manhattan Island, and is separated from Brooklyn to the east by the Buttermilk Channel. The National Park S ...

where the average rate of fire for the Springfield was 8 rounds per minute for new recruits and 15 rounds per minute for experienced soldiers. The board recommended "No. 99 Springfield" which became the ''model 1873''. After considerable testing, the prototype developed by Erskine S. Allin of the government-operated

was chosen for its simplicity and the fact that it could be produced by the modification of existing Springfield Model 1863 muskets. These modifications cost about $5 per rifle, which was a significant savings at a time when new rifles cost about $20 each. Patent No. 49,959 was issued to Erskine S. Allin on September 19, 1865, describing the design.

In fiction

The Springfield rifles with this modification. ''¨The Gun That Made One Man The Equal Of Five¨,'' come out in the epilogue of the action in the film

Springfield Rifle The term Springfield rifle may refer to any one of several types of small arms produced by the Springfield Armory in Springfield, Massachusetts, for the United States armed forces. In modern usage, the term "Springfield rifle" most commonly refer ...

(used to stop the thieves stealing horses for the Confederates).

Bibliography

*''Historical Dictionary of the U.S. Army'' by Jerold E. Brown, published by Greenwood Publishing Group, 2001 *''The .58 and .50 Caliber Rifles and Carbines of the Springfield Armory'' by Richard A. Hosmer, published by North Cape Publications, May 2006

References

External links