An assembly of a receiver (1) with a barrel (4) wherein the barrel (4) is inserted into a barrel hole (7) in the receiver (1) and is attached in a replaceable manner by means of a clamping connection that comprises a longitudinal slot (2) that longitudinally divides the receiver (1) wall in the insertion location of the barrel (4). In the location of the longitudinal slot (2) at least two transversal screws (3) pass through the receiver (1). In the location of the longitudinal slot (2), a transversal hole (5) extends into the receiver (1) and a transversal pin (10) passes through the transversal hole (5) in such a way that the transversal pin (10) reaches into a corresponding transversal recess (9) in the barrel (4). Perpendicularly to the longitudinal axis of the transversal pin (10) a threaded hole (11) with a connecting screw (12) passes through the transversal pin (10). The connecting screw (12) further passes through a straight-through hole (6) in the receiver (1) and through a stock/frame (13) of the firearm to connect the receiver (1) to the stock/frame (13) of the firearm.

An assembly of a receiver (1) with a barrel (4) wherein the barrel (4) is inserted into a barrel hole (7) in the receiver (1) and is attached in a replaceable manner by means of a clamping connection that comprises a longitudinal slot (2) that longitudinally divides the receiver (1) wall in the insertion location of the barrel (4). In the location of the longitudinal slot (2) at least two transversal screws (3) pass through the receiver (1). In the location of the longitudinal slot (2), a transversal hole (5) extends into the receiver (1) and a transversal pin (10) passes through the transversal hole (5) in such a way that the transversal pin (10) reaches into a corresponding transversal recess (9) in the barrel (4). Perpendicularly to the longitudinal axis of the transversal pin (10) a threaded hole (11) with a connecting screw (12) passes through the transversal pin (10). The connecting screw (12) further passes through a straight-through hole (6) in the receiver (1) and through a stock/frame (13) of the firearm to connect the receiver (1) to the stock/frame (13) of the firearm.