http://www.navweaps.com/Weapons/WNUS_6-50_mk5.htm 6"/50 Mark 5 Armstrong at NavWeaps.com] 4.7"/50 Mark 3 Armstrong at NavWeaps.com To reduce supply difficulties, during refits at the Cavite Navy Yard in the Philippines in 1903, both ships had their 4.7-inch guns replaced with standard  5 inches /50 caliber Mark 5 guns; the 6-inch guns were replaced with 5-inch guns in 1907. [