A retractable support assembly for a firearm. The assembly includes a swiveling support structure configured for attachment to or adjacent to the forward end of a firearm extension component on the firearm. The support structure is substantially centered on the longitudinal axis of the firearm barrel and permits movement of the longitudinal axis of the firearm barrel relative to a position fixed by deployment of the assembly for variable aiming of the firearm. The support structure has a central ball unit defined by a channel for passage of a barrel of the firearm. The ball unit is configured for rotatable movement within a socket formed by a rearward ball retention element and a forward ball retention element. The assembly includes a plurality of legs pivotably connected to the support structure for movement between an extended position and a retracted position.