"Enterprise" was armed with two 100-pounder smoothbore, muzzle-loading Somerset cannon and two rifled 110-pounder breech-loading guns. The breech-loading guns were of a new design from Armstrong and much was hoped for them. Firing tests carried out in September 1861 against an armoured target, however, proved that the 110-pounder was inferior to the 68-pounder smoothbore gun in armour penetration, and repeated incidents of breech explosions during the Battles for Shimonoseki and the Bombardment of Kagoshima in 1863–64 caused the navy to withdraw the guns from service shortly afterwards.