Two co-conspirators chose very different weapons on the night of April 14.
J. Wilkes Booth
John Wilkes Booth used a six-inch-long .44 caliber Deringer pistol to shoot President Lincoln, a gun so small that gamblers sometimes concealed them on their persons. The silver-clad gun made by Henry Deringer in his Philadelphia shop held only one shot, so Booth carried a long dagger as a backup.
Lewis Powell used a gun that dwarfed Booth’s — a three-pound Whitney revolver. The Confederate veteran aimed his long-barreled revolver at the Secretary William Seward’s son and yanked the trigger.
Fred Seward was still standing only because the revolver didn’t fire.
When he couldn’t shoot Seward, Powell used the heavy gun to pistol-whip him. Wielding it like a hammer, he clubbed Seward in the head repeatedly.
Powell only gave up when the firing pin became dislodged and the gun fell into pieces.
But, before he left, Powell stabbed the bedridden secretary in his face and neck, despite the best efforts of the secretary’s servant, his bodyguard and two of his sons.
Source: Wesley Harris address, “Tools of the Assassin, Part II,” Surratt Society Annual Conference, March16, 2013 and The Conspiracy Trial for the Murder of the President, and the Attempt to Overthrow the Government by the Assassination of its Principal Officers, U.S. Government