Until the 20th century, American ammo makers were sometimes rational in picking names for their cartridges. The .45/70, for example, was so-called because it was .45 caliber and held 70 grains of black powder. However, the signs of rot were already present. The .44 was actually .429. Why call it a .44? Possibly because .429 doesn't rhyme well, and cowboys couldn't write songs about it.