One bullet get lodged in the barrel in the previous firing and dislodged with the second bullet in the subsequent firing in

Tandem bullet( Piggy tail bullet) One bullet gets lodged in the barrel in the previous firing and dislodged with the second bullet in the subsequent firing. These bullets may separate before entering the body and produce two entrance wounds on a single firing. Sometimes, they may separate after entering the body and make two exit wounds. Sometimes, two bullets may remain inside the body making no exit wound. In some cases, one bullet will go producing one exit wound and the other will remain inside. In a single catridge, one bullet is set behind the other by notching on the base and in one shot two bullets are discharged. It is called duplex or tandem catridge. These types of catridges are used in some military rifles. Ref: FORENSIC MEDICINE AND TOXICOLOGY Dr PC IGNATIUS THIRD EDITION PAGE 141