A breech (103; 203; 303; 503; 603; 703; 803) for noise reduction in a recoil-less weapon, the breech (103; 203; 303; 503; 603; 703; 803) being adapted to be arranged in fluid communication with a launcher of the weapon to release exhaust gas, the breech (103; 203; 303; 503; 603; 703; 803) comprising: a venturi tube structure (215; 315; 515; 615; 715) having an inlet at a first end (313; 513; 613; 713) adapted to be connected to the launcher, and an outlet for releasing the exhaust gas at a second end (314; 514; 614; 714), wherein the area of the outlet is larger than the area of the inlet; and an exhaust gas controlling element (311; 511; 711) formed at the venturi tube structure, said exhaust gas controlling element (311; 511; 711) being arranged to control the release of exhaust gas so as to decrease a sound pressure peak at the weapon, the breech being characterized by that: the breech further comprises an additional exhaust gas controlling element comprising a porous body insertable in the venturi tube structure to successively release high pressure gas, and/or in that the exhaust gas controlling element (311; 511; 711) formed at the venturi tube structure comprises: a plurality of teeth arranged at the venturi tube circumference at the second end of the venturi tube structure (215; 315; 515; 615; 715) so that the exhaust gas controlling element at least controls the release of exhaust gas by successively releasing high pressure, or a gas channel formed at the exterior of the venturi tube structure and connected to an opening in the venturi tube structure, wherein the channel comprises a first channel part leading the gas in a direction substantially opposite the main gas flow direction in the venturi tube structure. a venturi tube structure (215; 315; 515; 615; 715) having an inlet at a first end (313; 513; 613; 713) adapted to be connected to the launcher, and an outlet for releasing the exhaust gas at a second end (314; 514; 614; 714), wherein the area of the outlet is larger than the area of the inlet; and an exhaust gas controlling element (311; 511; 711) formed at the venturi tube structure, said exhaust gas controlling element (311; 511; 711) being arranged to control the release of exhaust gas so as to decrease a sound pressure peak at the weapon, the breech being characterized by that: the breech further comprises an additional exhaust gas controlling element comprising a porous body insertable in the venturi tube structure to successively release high pressure gas, and/or in that the exhaust gas controlling element (311; 511; 711) formed at the venturi tube structure comprises: a plurality of teeth arranged at the venturi tube circumference at the second end of the venturi tube structure (215; 315; 515; 615; 715) so that the exhaust gas controlling element at least controls the release of exhaust gas by successively releasing high pressure, or a gas channel formed at the exterior of the venturi tube structure and connected to an opening in the venturi tube structure, wherein the channel comprises a first channel part leading the gas in a direction substantially opposite the main gas flow direction in the venturi tube structure. a plurality of teeth arranged at the venturi tube circumference at the second end of the venturi tube structure (215; 315; 515; 615; 715) so that the exhaust gas controlling element at least controls the release of exhaust gas by successively releasing high pressure, or a gas channel formed at the exterior of the venturi tube structure and connected to an opening in the venturi tube structure, wherein the channel comprises a first channel part leading the gas in a direction substantially opposite the main gas flow direction in the venturi tube structure.