Seeking information for UMC 4570 cartridges|What's New!|Forum|Winchester Collector

I have two sealed boxes and one open box of 4570 cartridges I am trying to get information on. On the box it has : For u s Government and Winchester Rifles, 45 Calibre, smokeless powder, 432 grs, soft point bullet.4570 government flat point. on the bottom of the cartridge it has 45 gov and umc. any help would be appreciated.