There is a good deal of information in this 1918 magazine article pertaining to the abilities of the 1903 Springfield rifle as well as the amount of cartridges issued to both British and German soldiers during the First World War:
"The American infantryman's belt has ten pockets holding two clips of 5 cartridges each, or 100 rounds of ammunition and in addition, when going into action, he carries two bandoleers containing 60 cartridges each..."
When the Doughboys complained, they complained heartily about their uniforms; read about it here.
