Weapon systems in the nature of firearms; weapon attachments in the nature of modular external rail systems for firearms, modular external rail systems for attaching accessories to firearms, mounts for attaching accessories to a firearm, mounts for attaching ancillary equipment to a firearm, mounts for attaching grips to a firearm, mounts for attaching gun sights to a firearm, mounts for attaching pointing devices to a firearm, mounts for attaching lighting to a firearm, mounts for attaching ...