Complex sentence: The.455 cartridge was one of the great service revolver cartridges, being a rimmed cartridge firing a 265-grain (17.2 g).45 bullet at the relatively low velocity of 620 ft/s (190 m/s).
Split into simpler sentences: The.455 cartridge was one of the great service revolver cartridges. It was a rimmed cartridge that launched a 265-grain (17.2 g).45 bullet at the relatively low velocity of 620 ft/s (190 m/s).