Abstract: A grenade machine gun or other weapon which employs superelevation of the barrel comprises a barrel unit and an aiming system mounted upon a support. The aiming system is mounted to the weapon and the support by a coupling unit. The aiming system comprises an imaging and display unit for displaying an image of a scene including a target, angle encoders for providing a signal representing displacement of the imaging unit in elevation relative to the support, and a control unit, e.g. a computer, for selecting either of two states for the coupling unit. The first state entrains the imaging unit to move with the barrel. The second state secures the imaging unit to the support and allows the barrel to move relative to both, i.e. during superelevation of the barrel. The coupling unit may comprise a first part connected to the weapon for rotation in elevation with the barrel unit and a second part connected to the imaging unit.

Abstract: A mounting for mounting an article onto a support comprising upper and lower mounting members. Seating surfaces provided between the members retain the members in assembled relationship with the members immovably registered together in a first plane. Three spaced mounting member registration projections provide, in the assembly, contact between the mounting members in three spaced and staggered positions on opposite sides of one of the mounting members, and registration to hold the members immovably together in a second plane. Spring-loaded locking is provided to hold the members together when assembled. Preferably the registration projections are provided on one member upon guide surfaces which are converging and inclined towards a respective seating surface. Guide surfaces on the other member are correspondingly converging and inclined.