Mark 8 nuclear bomb

The Mark 8 was a gun-type nuclear bomb, which rapidly assembles several critical masses of fissile nuclear material by firing a fissile projectile or "bullet" over and around a fissile "target", using a system which closely resembles a medium-sized cannon barrel and propellant.

The Mark 8 was an early earth-penetrating bomb (see nuclear bunker buster), intended to dig into the earth some distance prior to detonating.

"[2] The Mark 8 was considered as a cratering warhead for the SSM-N-8 Regulus cruise missile.

A lighter Mark 8 variant, the Mark 10 nuclear bomb, was developed as a lightweight airburst (surface target) bomb.

The Mark 10 project was cancelled prior to introduction into service, replaced by the much more fissile-material-efficient Mark 12 nuclear bomb implosion design.