Abstract: A self propelled gun (2) comprises a vehicle (4) possessing a source of primary power (6) and a gun assembly (8) movably attached to the vehicle. The gun assembly (8) comprises a base (10), a cradle (14) pivotally mounted to the base and a barrel (16) slidably mounted to the cradle (14) such as to be displaceable from a first, run-out, position to a second, recoiled, position as a consequence of the barrel (16) recoiling on firing. The gun assembly (8) is movably mounted to the vehicle (4), preferably by a pivot arrangement (24, 26) between vehicle (4) and base (10), such that in a first, “mobility”, mode the gun assembly (8) is free of any direct contact with the ground (42), and said barrel (16) points in a first direction allowing said vehicle (4) to be driven and a second, “firing”, mode of operation in which the gun assembly is deployed to a firing position in which the base moves towards and into engagement with the ground (42).