In recent years, the railgun focus has switched to developing tactical weapons with launch velocities of 2 to 3 km/s. The projectile focus for tactical weapons has switched from plasma to solid armatures because of their high efficiency. Since few measurements have been made on the state of the solid armature during an electromagnetic launch, new diagnostics need to be developed to substantiate theoretical models. This paper presents several recent developments in the area of railgun instrumentation that attempt to directly or indirectly measure physical quantities that relate to the function of a solid armature during a launch.