 From 1875 onwards , the balance between <unk> and muzzle @-@ loading changed . Captain de <unk> invented a method of reliably sealing a breech , adopted by the French in 1873 . Just as compellingly , the growing size of naval guns made muzzle @-@ loading much more complicated . With guns of such size there was no prospect of hauling in the gun for re @-@ loading , or even re @-@ loading by hand , and complicated hydraulic systems were required for re @-@ loading the gun outside the turret without exposing the crew to enemy fire . In 1882 , the 81 @-@ ton , 16 @-@ inch ( 406 mm ) guns of HMS Inflexible fired only once every 11 minutes while bombarding Alexandria during the Urabi Revolt . The 100 @-@ ton , 450 mm ( 17 @.@ 72 inch ) guns of Caio Duilio could each fire a round every 15 minutes . 
