The invention relates to a single-shot rifle, comprising a receiver (1), a barrel (6) which is attached to the receiver (1), a bolt (8) housing a firing pin (24), located in correspondence with the back end of the barrel (6), wherein the bolt (8) and the back end of the barrel (6) are configured such that the bolt (8) can be coupled to the back end of the barrel (6) by means of a sliding movement in a direction perpendicular to the longitudinal direction, such that the bolt (8) can travel between a loading position in which it leaves the back end of the barrel (6) clear such that the user can introduce a bullet in a chamber of the barrel (6) through said back end of the barrel (6), and a firing position in which said chamber is locked by said bolt (8), the barrel (6) and the bolt (8) being attached by means of at least one rib (61) entering at least one channel (81).