Air gun system including: - a body forming an internal volume, - control means designed to trigger firing, - a main inlet that is intended to be connected to a compressed-air source and leads into said internal volume of the body, - a main outlet that is connected to the internal volume of the body and is intended to expel compressed air to the outside, - a main piston that is movable between two positions, a first position closing off said main outlet and a second position opening said main outlet, - characterized in that it includes: - a pneumatic device designed to create a sufficient pressure difference to return the main piston to its first position and which has a control member controlled by a movement of the main piston from its first position to its second position, a secondary compressed-air source and at least one volume in contact with said main piston and into which said secondary compressed-air source opens, and in that the control member is designed to control the feed of said volume by the secondary feed source, - said control member having a secondary piston that is movable between two positions, referred to as first position and second position, - the pneumatic device having a pressure chamber in which said main piston and said secondary piston move and comprising said volume, said volume being adjustable between said main piston and said secondary piston and being intended to be fed by said secondary compressed-air source, - means for rearming said pneumatic device. - a body forming an internal volume, - control means designed to trigger firing, - a main inlet that is intended to be connected to a compressed-air source and leads into said internal volume of the body, - a main outlet that is connected to the internal volume of the body and is intended to expel compressed air to the outside, - a main piston that is movable between two positions, a first position closing off said main outlet and a second position opening said main outlet, - characterized in that it includes: - a pneumatic device designed to create a sufficient pressure difference to return the main piston to its first position and which has a control member controlled by a movement of the main piston from its first position to its second position, a secondary compressed-air source and at least one volume in contact with said main piston and into which said secondary compressed-air source opens, and in that the control member is designed to control the feed of said volume by the secondary feed source, - said control member having a secondary piston that is movable between two positions, referred to as first position and second position, - the pneumatic device having a pressure chamber in which said main piston and said secondary piston move and comprising said volume, said volume being adjustable between said main piston and said secondary piston and being intended to be fed by said secondary compressed-air source, - means for rearming said pneumatic device. - a pneumatic device designed to create a sufficient pressure difference to return the main piston to its first position and which has a control member controlled by a movement of the main piston from its first position to its second position, a secondary compressed-air source and at least one volume in contact with said main piston and into which said secondary compressed-air source opens, and in that the control member is designed to control the feed of said volume by the secondary feed source, - said control member having a secondary piston that is movable between two positions, referred to as first position and second position, - the pneumatic device having a pressure chamber in which said main piston and said secondary piston move and comprising said volume, said volume being adjustable between said main piston and said secondary piston and being intended to be fed by said secondary compressed-air source, - means for rearming said pneumatic device.