.45-70 Blank Ammunition (For use in Real Guns) Box of 50 The .45-70 is also known as the .45-70 Government. It is a .45 caliber rifle cartridge developed to be used in the Springfield Model 1873. It originally contained 70 grains of powder and was created at U.S. Army's Springfield Armoury. Blank cartridges will not cycle automatically without the use of a blank-firing adapter.