Springfield “Trapdoor” - The U.S. Army’s First Standardized Rifle

At the close of the Civil War, the United States Army had a stockpile of approximately one-million .58 caliber rifled muskets. It was a sizable and expensive cache of weapons that were on the verge of becoming obsolete. 

With a new age of repeating arms dawning and inventions such as smokeless powder, metallic cartridges growing in popularity, the landscape of the battlefield was primed for change. Guns such as the Henry Rifle and the Spencer Carbine had already proven their worth in battle, so the Army was left with a big decision to make about what should be done with this massive arsenal of outdated rifles? Issuing them to troops could be detrimental to the safety of the soldiers, and not using them would be a wasteful expense that the Army could ill afford.

With the experience of war still swirling in the government's mind, now the focus was on being prepared for any future conflicts. Most decision-makers were of the mindset, that if another war were to happen, it would likely be against a foreign army carrying single shot rifles. This made them feel that a feasible remedy would be to develop a breech loading conversion for these muskets. This would enable them to maintain a level battlefield with the arms being carried by any potential opposing forces, and still continue to allow the conservation of ammunition with a single shot rifle. 

Prior to the start of the Civil War, the U.S. Army had already begun the research for adopting a centerfire cartridge, and a mechanism that was known as the Morse breech loading system. However, the onset of the war brought an immediate stop to all production and development of these things. The Army had to direct their energy to the production of guns quickly to arm the troops for battle. But once the war had ended, and it became apparent to many that the Army was going to resume their focus on such endeavors, countless inventors suddenly began trying to sell their conversion patents to the government.

During this time a Master Armorer at the National Armory at Springfield named Erskine S. Allin had already been instructed to begin working on such a conversion. Allin had access to many of the previous samples that had been submitted and stored at the armory, so it didn’t take him long to narrow his focus on what he felt would be the best solution. His first prototype was built using a Springfield Model 1861 Musket. He cut away the rear of the barrel to access the chamber and installed a cam-locked breech block.

He continued to work on improving this concept for a number of years, and offered several variations of his “Trapdoor” design during his time at the Springfield Armory. Although, gaining the trust and acceptance from the Army was not as simple as just handing over a working sample.  Back then, bureaucracy played a big role in the final decision making.  

The first of Allin’s guns to actually be tested out by troops was built using 1863 Muskets. These rifles would be designated as the Springfield Model 1865. However, it was quickly realized that the mechanics of the gun, and more specifically the extraction system, were not going to be strong enough to offer consistent reliability, so no declaration of official acceptance was ever made.

Allin went back to work and replaced the extraction system with a more meticulous design using a series of springs. This next rifle would also be fitted with a new centerfire cartridge, the .50-70, which had been developed by Steven Vincent Benet of the Frankford Arsenal. Though it was not standardized, the .50-70 cartridge would become the first widely used centerfire cartridge by the U.S. Army. To accommodate this new cartridge each of the rifles would be bored out and relined with either steel or iron rifled bores, which increased the weight of each gun to well over 10 lbs. These guns are often referred to as the Second Allin Conversion or the Springfield Model 1866.

Now by this point, the government had convened the Laidley Board and tasked the board with selecting a new breech-loading rifle for official adoption. The board considered many quality and durable designs, such as the Remington Rolling Block and the Sharps Falling Block rifles, but not the Springfield Allin conversions, because they were thought to be under development and therefore ineligible for final selection. The board would ultimately recommend adoption of a forerunner to the Martini-Henry known as the Peabody Conversion.

This recommendation was not well received and immediately provoked protest. American inventors and wealthy businessmen were among the many folks that saw the need to travel to Washington, and formally air their grievances with the board’s decision. The government offered little resistance to these protests, and made a request for the board to reconvene and instructed it to give consideration to what the Springfield Armory had to offer. 

The result of this second board review lead to the selection of the improved Allin Conversion. It was the Springfield Model 1866, and it would be the first of these “trapdoor” rifles to see real use by the Army. It was issued to the men who were stationed along the Bozeman Trail. The soldiers armed with the Allin rifles were tasked with protecting the flood of settlers traveling by wagon train along this route during the Gold Rush. 

The use of the trail had been outlined by the Fort Laramie Treaty of 1851, but with a number of Native American nations located along its route, the threat of hostility was never thought to be completely out of the question. This is why the Army saw the need for troops to remain there as peacekeepers. Ironically, it would be a group of these peacekeeping soldiers that would spark a conflict with the natives. The soldiers had set out to locate a horse thief that they believed to be in a nearby teepee village, and while they were there attempting to locate him, the tribes chief was shot and killed. All of the soldiers in the group were immediately slaughtered and larger hostilities arose as a result. A part of the treaty had stated that the white men and the natives would each handle their own discipline, which the soldiers had essentially ignored and therefore broke the agreement.

In retaliation, the Sioux nation lead by Chief Red Cloud, attacked two of the nearby Army posts that were established along the trail. This would be the first real test in battle for the Allin Conversion rifle. The rapid fire of the Model 1866 took the native warriors by surprise, and ultimately aided in defending the posts. However, the rifle, as we have seen with countless others, quickly exposed its shortcomings under such stress. So once again, Erskine Allin would take what he had learned and make the necessary corrections to his “Trapdoor” Springfield. 

The major issue reported was a separation of the barrel lining. The solution was to use a completely new barrel which would be attached to a separate Allin type receiver.  The new barrel was four inches shorter, and was attached using only two barrel bands, as opposed to the three bands that held the barrel on the 1866. It was also equipped with a newly developed rear sight that allowed for elevation adjustment by means of a sliding bar with an aperture. Another issue was the weakness of the extractor mechanism. To resolve it, the reworked rifles were the first ones to use a new type of simplified cartridge extractor. These guns were named the Springfield Model 1868, and would reach an estimated total production of 52,000 rifles. Many of the remaining 1866 rifles would then be sold to France to be used in the Franco-Prussian War.

The 1868 would see just limited production before even more modifications were made. The Springfield Model 1870 would be given a shorter and stronger receiver, and would quickly replace the 1868. It would also receive a new caliber, the .45-70, which had been selected by a board of officers who had been convened to conduct trials at the Frankford Arsenal. The 1870 would be tested in the Terry Board Trials (headed by and named after Brigadier General Alfred H. Terry) against ninety-nine breech loading actions that included those being developed by Remington, Sharps, and Ward-Burton.

Through these trials, the Army intended to completely standardize their arsenal. By this time, they were years removed from the Civil War, but yet the troops were still using a mixed bag of weaponry. The government agreed that a simplified arsenal was needed, so to accommodate this standardization, Congress decided to appropriate a conditional $150,000 to the National Armory. The funds came with a stipulation that the board must first select a standardized breech-loading system and do so within the confines of the 1872 / 1873 fiscal year budget. 

The board would test all of the rifles extensively and was starting to lean towards a magazine-fed Ward-Burton rifle. However, this rifle had issues with durability and safety, which needed to be addressed, and time was quickly running out on the board’s decision. So rather than lose the funds and begin the process all over, Secretary of War William W. Belknap selected the reliable Allin system as the standardized breech-loading mechanism. Some historians speculate that the fact the Allin was a government employee, which may have limited his ultimate compensation, was a decisive factor. We could not prove or disprove this assumption.

Nevertheless, the .45-70 Springfield rifle became the first standard issue rifle of the U.S. Army and remained in service for decades. Even after the turn of the century and adoption of the U.S. Krag, the Springfield “trapdoor” remained a secondary service weapon. 

Over the years the .45-70 Springfield would be improved upon in small increments. The stock would be strengthened by lengthening the comb and shortening its wrist. Tweaks to the receiver and breech block would help divert gases away from the shooter to prevent injury in the event of a case rupture. 

Without a doubt the .45-70 Springfield became the best known of all of Erskine Allin’s “Trapdoor” designs. It has received both praise and criticism, but regardless of one's opinion, there can be no denying its place in the history of our military.

In fact, it played a role in one of our nation's most famous conflicts. At the Battle of Little Big Horn in 1876, it was the Springfield “Trapdoor” rifle that armed many of Lt. Col. George Armstrong Custer’s men. Although, it ended in disaster for the Army, and some folks were quick to point a finger at the “Trapdoor” rifle, it was later determined that poor strategy and a wealth of misinformation were actually at fault for Custer’s demise, and not a faulty rifle.

The battle did however provoke a further modification of the “Trapdoor” Springfield. When it was believed that better accuracy from their defensive post would have changed the course of the battle, a rear sight was developed that offered both windage and elevation adjustments. The Buffington rear sight would first appear on the Springfield Model 1884 “Trapdoor” rifle.

Today a single shot rifle wouldn’t suit the needs for very many applications, never mind as an infantry weapon. However, for much of the nineteenth century and beyond, the deciding powers believed untrained troops would waste their costly ammunition if they were provided more firepower. Luckily the logical conclusion of better preparing troops for battle prevailed, and inventors since then have continued to astonish us with the extent of their imaginations.  Although no matter what modern firearm inventors manage to achieve, there will always be a debt of gratitude due to men like Erskine Allin, whose determination and creativity helped advance the industry.

The Springfield “Trapdoor” rifles remain some of the most recognizable and collectible guns ever made. The simple fact that so many working samples still exist today proves that Allin didn’t just solve the problem of finding a use for a million outdated muskets, he built an American treasure that exemplifies our resolve and ingenuity as a nation.