Frankford Arsenal, Union Metallic Cartridge (UMC) Company, and Remington each produced triplex multiball loads. Based on the work of Capt. E.M. Wright, the Frankford Arsenal loads used three 133 grain round balls and 45 grains of black powder. Examples of these have been found using a copper case and the Benét Cup Inside Primer. The UMC multiball loads date from 1902-03 and use conventional primers and brass cases. (It is alleged that UMC only provided the cases, and Frankford manufactured the rounds in question.) Remington produced two million multiball cartridges during 1917 as old Springfield Trapdoors were being reissued to guards at various military installations.