As you destroy the ship you would destroy components of the ship, not just the hull and armor.  Some of the weapons would be damaged as the overall damage to the ship nears the point of exploding.  

In addition to the damage to the weapons, the crew would be reduced (killed/wounded) or at least they would be temporarily forced to abandon their stations as they catch fire or become exposed to the vaccum of space.  

Maybe as a ship reaches some damage level, like 50%, they might start losing some of their guns and missile launchers temporarily until damage control can effect some repairs?