The Spencer repeating rifles and carbines were early American lever-action firearms invented by Christopher Spencer. The Spencer was the world's first military metallic cartridge repeating rifle, and over 200,000 examples were manufactured in the United States by the Spencer Repeating Rifle Co. and Burnside Rifle Co. between 1860 and 1869. The Spencer repeating rifle was adopted by the Union Army, especially by the cavalry, during the American Civil War but did not replace the standard issue muzzle-loading rifled muskets in use at the time. Among the early users was George Armstrong Custer. The Spencer carbine was a shorter and lighter version designed for the cavalry.
The design for a magazine-fed, lever-operated rifle chambered for the .56-56 Spencer rimfire cartridge was completed by Christopher Spencer in 1860. Called the Spencer Repeating Rifle, it was fired by cocking a lever to extract a used case and feed a new cartridge from a tube in the buttstock. Like most firearms of the time, the hammer had to be manually cocked after each round in a separate action before the weapon could be fired. The weapon used copper rimfire cartridges, based on the 1854 Smith & Wesson patent, stored in a seven-round tube magazine. A spring in the tube enabled the rounds to be fired one after another. When empty, the spring had to be released and removed before dropping in fresh cartridges, then replaced before resuming firing. Rounds could be loaded individually or from a device called the Blakeslee Cartridge Box, which contained up to thirteen (also six and ten) tubes with seven cartridges each, which could be emptied into the magazine tube in the buttstock.
Unlike later cartridge designations, the .56-56 Spencer's first number referred to the diameter of the case just ahead of the rim, the second number the case diameter at the mouth; the actual bullet diameter was .52 in (13 mm). Cartridges were loaded with 45 grains (2.9 g) of black powder, and were also available as .56-52, .56-50, and a wildcat .56-46, a necked down version of the original .56-56. Cartridge length was limited by the action size to about 1.75 in (44 mm); later calibers used a smaller diameter, lighter bullet and larger powder charge to increase power and range over the original .56-56 cartridge, which was almost as powerful as the .58 caliber rifled musket of the time but under-powered by the standards of other early cartridges such as the .50–70 and .45-70.
When Spencer signed his new rifle up for adoption right after the Civil War broke out, the view by the Department of War Ordnance Department was that soldiers would waste ammunition by firing too rapidly with repeating rifles, and thus denied a government contract for all such weapons. (They did, however, encourage the use of breech-loading carbine, which is also single-shot like most firearms of the day, but is shorter than standard rifles and thus more suited to mounted warfare) More accurately, they feared that the Army's logistics train would be unable to provide enough ammunition for the soldiers in the field, as they already had grave difficulty bringing up enough ammunition to sustain armies of tens of thousands of men over distances of hundreds of miles. A weapon able to fire several times as fast would require a vastly expanded logistics train and place great strain on the already overburdened railroads and tens of thousands of more mules, wagons, and wagon train guard detachments. Its unit cost (several times that of a Springfield Model 1861 rifled musket) also stood in the way. However, shortly after the famous Battle of Gettysburg, Spencer was able to gain an audience with President Abraham Lincoln, who invited him to a shooting match and demonstration of the weapon on the lawn of the White House. Lincoln was deeply impressed with the weapon, and ordered Gen. James Wolfe Ripley to adopt it for production. Ripley disobeyed the order and continued to use the old single-shooters.
The Spencer repeating rifle was first adopted by the United States Navy, and later by the United States Army, and it was used during the American Civil War, where it was a popular weapon. The Confederates occasionally captured some of these weapons and ammunition, but, as they were unable to manufacture the cartridges because of their dire copper shortage, their utilization of the weapons was limited. Gettysburg was the first major battle of the war where Spencer rifles were used, as they had recently been issued to the 13th Pennsylvania Reserves. They were used at the Battle of Chickamauga and had become fairly widespread in the Western armies by 1864. Repeater rifles for comparison were rare in the Army of the Potomac.
Notable early instances of use included the Battle of Hoover's Gap (where Colonel John T. Wilder's "Lightning Brigade" of mounted infantry effectively demonstrated the firepower of repeaters), and the Gettysburg Campaign, where two regiments of the Michigan Brigade (under Brigadier General George Armstrong Custer) carried them at the Battle of Hanover and at East Cavalry Field. As the war progressed, Spencers were carried by a number of Union cavalry and mounted infantry regiments and provided the Union army with a firepower advantage over their Confederate opponents. At the Battle of Nashville, 9,000 mounted infantrymen armed with the Spencer, under the command of Maj. Gen. James H. Wilson, chief of cavalry for the Military Division of the Mississippi, rode around Gen. Hood's left flank and attacked from the rear. President Lincoln's assassin John Wilkes Booth was armed with a Spencer carbine at the time he was captured and killed.
The Spencer showed itself to be very reliable under combat conditions, with a sustainable rate-of-fire in excess of 20 rounds per minute. Compared to standard muzzle-loaders, with a rate of fire of 2–3 rounds per minute, this represented a significant tactical advantage. However, effective tactics had yet to be developed to take advantage of the higher rate of fire. Similarly, the supply chain was not well prepared enough to transport the extra ammunition. Detractors also complained that the amount of smoke produced was such that it was hard to see the enemy, which was not surprising since even the smoke produced by muzzleloaders would quickly blind whole regiments, and even divisions as if they were standing in thick fog, especially on still days.
One of the advantages of the Spencer was that its ammunition was waterproof and hardy, and could stand the constant jostling of long storage on the march, such as Wilson's Raid. The story goes that every round of paper and linen Sharps ammunition carried in the supply wagons was found useless after long storage in supply wagons. Spencer ammunition had no such problem owing to the new technology of metallic cartridges.
1867 Brigadier General James F. Rusling of the Quartermaster's Dept. recommended exclusive use of the carbine on cavalry against mounted Indians raiders after completing a 1-year tour of the new western territories.
In the late 1860s, the Spencer company was sold to the Fogerty Rifle Company and ultimately to Winchester. Many Spencer carbines were later sold as surplus to France where they were used during the Franco-Prussian War in 1870.
Even though the Spencer company went out of business in 1869, ammunition was manufactured in the United States into the 1920s. Later, many rifles and carbines were converted to centerfire, which could fire cartridges made from the centerfire .50-70 brass. The original archetype of rimfire ammunition can still be obtained on the specialty market.