Shock cannons are turret-mounted anti-electron guns.
The turrets of the Yamato are able to switch between Shock Cannon mode and Projectile mode. In Shock Cannon mode, all three turrets will fire anti-electron pulses simultaneously. It has been shown that these anti-electron beams can easily reach targets with distances exceeding several thousand kilometers away. It is also very possible that conventional Type-3 shells are armed with megaton-size nuclear warheads.
At short ranges, the anti-electron beams will be three separate beams. As they travel further, the mutual interaction between the beams will cause them to gradually spiral together until they travel as a single co-rotating higher-intensity anti-electron beam.
The shock cannons have been shown to be able to cut or pierce trough any Gamillas ship armor except for the frontal hull armor of larger battleships such as Dreadnoughts. However, as with any other beam weapon, they will dissipate within a short range in subspace and is ineffective in such a situation.