A modular gun-launch projectile is provided to include a core section; a base section, a payload section and a nose section. The base section can be translatably inserted into the core section. The payload section includes an annular opening that enables the core section to pass therethrough. The nose section can be inserted into the core section. The sections are separable into discrete components and can be assembled together into an all-up-round. The core section can be a cylindrical solid rod or cylindrical hollow tube. The base section can include a propulsion system. The payload section can be a unitary explosive or contain submunitions. The nose section can include a fuse, a seeker, an air inlet, a guidance receiver and/or guidance vanes.