The .54 Burnside carbine was designed and patented by Ambrose E. Burnside in 1855 and was manufactured in Rhode Island by the Bristol Firearms Company which later became the Burnside Rifle Company. It was the third most widely used carbine by the Union cavalry, exceeded only by the Sharps and Spencer carbines. The trigger guard also served as the operating lever and it was lowered, causing breech to tilt up, revealing a cone-shaped cavity to fit the cartridge. The flange around the bullet contained the lubricant for the bullet. Closing the lever rotated the breech block into position, placing the cartridge in the chamber. A percussion ignition system with an external hammer fired the carbine. A small hole at the base of the cartridge would allow the fire to pass through and ignite the powder in the case. Despite the popularity of the Burnside, there were a lot of complaints about cases stuck in the breech after firing.