A breech mechanism in artillery where the breechblock slides vertically downward to open or close the breech.

High Explosive (HE) round: an artillery or mortar projectile containing explosive filler designed to inflict damage through blast and fragmentation effects.

Operated, moved, or controlled by fluid pressure, typically oil, used in mechanisms like recoil systems to absorb and manage energy.

Artillery classification distinguishing self-propelled wheeled vehicles from weapons towed by external means.