A manufacturing procedure for a “bull barrel” model with silencer and “model bull barrel” with obtained silencer.It comprises the following stages: a first stage in which a tube (2), which defines two ends, a first (21) and a second (22), with an interior diameter that exceeds the outer diameter of the barrel (1), fixed to a wedge (19) by its first end (21), a second stage in which a muzzle (5) that ends in a hood (10) is fixed to the second end (22) of tube (2), with said muzzle (5) comprising at least one lateral aperture (6) and at least one first hoop (8) that fits inside the tube (2) sealing the second end (22), similarly with stops (7) that define channels (11) in the hood (10) that connect the exterior with the inside of the muzzle (5), with the mentioned stops (7) forming the end of travel for the referred tube (2), a third stage in which the barrel (1) is fixed to the muzzle (5) and to the wedge (19), thus defining a space or cavity (3) between the tube (2) and barrel (1) and a fourth stage in which the third stage configuration is inserted into a molding machine for over-molding, except for the barrel entrance end (14), giving it the desired shape, with said end penetrating said over-molding (20) towards the inside of the tube (2) by the channels (11) up to the referred first hoop (8).