Reconversion device for a gun from semi-automatic to pump operation

Reconversion device from a semi-automatic operation of the fixed barrel type using the kinetic recoil energy of the arm for the ejection of the cartridge and the recocking of the arm and comprising a breech bolt head separated from the breech bolt with a spring freely interposed between them, to a pump system, characterized in that it comprises an annular control handle rotatably supported on a ring secured to an end of a tubular cocking rod axially slidable on a tubular magazine, said handle and said ring being provided with means for their mutual snap action engagement in four positions at 90.degree. to one another, said handle having, projecting from an end front face thereof, two diametrically opposite sectors each ending in a tooth and the front face of a support of the magazine, secured to the barrel, facing the end front face of the handle having an annular recess with two diametrically opposite passages having a height larger than that of the remaining annular recess, said recess communicating with an annular undercut groove in the support, the two passages of the annular recess having a larger height being adapted to receive the teeth of the two sectors projecting from the end front face of the handle, the four snap engagement positions of the handle and the ring secured to the cocking rod corresponding, alternatively, to the engagement of the teeth of the two sectors in the undercut groove in the support of the magazine and the disengagement of the teeth of the two sectors from said undercut groove.