Damage/particlebeam

From UFO:AI

Extremely high-speed projectile weaponry that can punch through heavy armor. Delivers damage by transferring the kinetic force of the projectile to the target. Excellent for high-armour environments. However, the projectile is moving at such a high speed that it can pass through a soft target without transferring much of its kinetic force (ie - it doesn't lose speed). As a result, it will do less damage to an unarmored target.