What was a "unit of fire" in the nonfiction book, With the Old Breed, at Peleliu and Okinawa?

A unit of fire was the approximate amount of ammunition, determined from experience, a unit would expend in one day of heavy fighting. It included 100 rounds for each M-1 rifle; 45 rounds for each M-1 carbine; 14 rounds for each .45 colt; 1,500 rounds for each light machine gun; and 100 rounds for each 60mm mortar in the unit.