A regenerative braking system, comprising: a barrel comprising a bore; a circuit including a plurality of electrically conductive components distributed along a length of the bore; a projectile comprising at least one of a conductive material or a magnetic material magnetically coupled to the electrically conductive components when the projectile is moving along the length of the bore; and wherein: the circuit is configured to store energy generated from an electric current induced in the electrically conductive components when the projectile moving along the length of the bore causes a magnetic interaction between the electrically conductive components and the at least one of the magnetic material or the conductive material, and the magnetic interaction is configured to cause braking of the projectile, characterized in that the regenerative braking system further comprises a connector configured to attach the barrel to a muzzle of a firearm, wherein the projectile comprises a bullet configured to be fired into the barrel from the muzzle, wherein: the barrel comprises a vent positioned forward of the electrically conductive components, and wherein the vent is configured to vent an exhaust from the firearm. a barrel comprising a bore; a circuit including a plurality of electrically conductive components distributed along a length of the bore; a projectile comprising at least one of a conductive material or a magnetic material magnetically coupled to the electrically conductive components when the projectile is moving along the length of the bore; and wherein: the circuit is configured to store energy generated from an electric current induced in the electrically conductive components when the projectile moving along the length of the bore causes a magnetic interaction between the electrically conductive components and the at least one of the magnetic material or the conductive material, and the magnetic interaction is configured to cause braking of the projectile, characterized in that the regenerative braking system further comprises a connector configured to attach the barrel to a muzzle of a firearm, wherein the projectile comprises a bullet configured to be fired into the barrel from the muzzle, wherein: the barrel comprises a vent positioned forward of the electrically conductive components, and wherein the vent is configured to vent an exhaust from the firearm. the circuit is configured to store energy generated from an electric current induced in the electrically conductive components when the projectile moving along the length of the bore causes a magnetic interaction between the electrically conductive components and the at least one of the magnetic material or the conductive material, and the magnetic interaction is configured to cause braking of the projectile, characterized in that the regenerative braking system further comprises a connector configured to attach the barrel to a muzzle of a firearm, wherein the projectile comprises a bullet configured to be fired into the barrel from the muzzle, wherein: the barrel comprises a vent positioned forward of the electrically conductive components, and wherein the vent is configured to vent an exhaust from the firearm.