A replacement cylinder that enables the use of modern smokeless gunpowder in a black powder muzzle-loading revolver is provided. The cylinder includes a main cylinder body and a removable cylinder cap. The main cylinder body includes a number of chambers, each of which having a projectile portion, a propellant portion and a primer portion. The cylinder cap includes a number of captured firing pins positioned therein. During operation, the cylinder cap is allowed to axially translate relative to the main cylinder body. A method of muzzle-loading the cylinder of the invention using modern smokeless gunpowder and a primer is also provided and is facilitated by the provision of a loading plate.