What makes this rifle revolutionary is that it is a breech-loading model. The user opened the breech block for loading a cartridge simply by first pressing the weapon’s two trigger guards and then insert-ing a special brass cartridge, also invented by Burnside, to go into his new carbine. Whenever the user squeezed the trigger, the hammer fell on a percussion cap (self contained metal cartridges would not be invented for several years) and caused a spark; a hole in the base of the cartridge exposed the black powder to this spark. The unique, cone-shaped cartridge sealed the joint between the barrel and the breech. Most other breech-loading weapons of the day tended to leak hot gas when fired, but Burnside’s design had effectively eliminated this problem.
In 1857, the Burnside carbine won a competition at West Point against 17 other carbine designs that were vying for a contract to supply arms for the military. In spite of its proven superiority, few of the carbines were immediately ordered by the government. But then something happened that changed the fortunes of the company, and of the rifle’s creator. What happened? The Civil War happened. When the war opened, there was a sudden need for a great increase in the standing army, as many of the men left the Union Army to join the rebel army. But what were these new soldiers to shoot? The War Department decided to order 55,000 rifles for use by Union cavalrymen. This made it the third most popular carbine of the Civil War; with only the Sharps carbine and the Spencer carbine being more widely used in all theaters of the war. There were so many in service that many were captured and used by Confederates. A common complaint made by most of the men who used the Burnside carbine was that the unusually shaped cartridge sometimes became stuck in the breech after firing.
A review of both the ordnance returns (arms returned to the Army after the war or at other times) and the schedule of ammunition requisitions indicates that approximately 43 Union cavalry – as well as at least seven Confederate cavalry — regiments were using the Burnside carbine during the 1863-1864 period. The end of the war saw the end of production of the Burnside rifle, when the Burnside Rifle Company was given a contract to make Spencer carbines instead.
And what of the inventor? What happened to his career? Despite his being in the Army prior to the war, he had resigned to focus his energy on his new company, A. E. Burnside gained his promotions because of his carbine. A. E. Burnside, Ambrose E. Burnside, to give his name in full, was actually a military failure due to his lack of confidence in his skills. He had repeatedly turned down command of the Army of the Potomac when President Lincoln pushed the job on him, telling the President “I was not competent to command such a large army as this. Eventually, however, Burnside gave up refusing and accepted the command. He immediately led the Army of the Potomac to defeat at the Battle of Fredericksburg. The battle and the subsequent abortive offensive left many of Burnside’s officers en-raged and they eloquently and loudly expressed their rage to both the White House and the War Department about Burnside’s incompetence.” He also performed poorly at the Battle of Spotsylvania Court House, and a subsequent court of inquiry also found him responsible for the Union failure at the Battle of the Crater.