When Annie goes to purchase a Desert Eagle .50 Cal pistol, she asks for 125 grain ammo. 125 grains would be more appropriate to .38 Cal ammo. .50 Cal ammo for a Desert Eagle is more likely to be 325 grains. This is a measure of the weight of the bullet fired from the cartridge. There are 437.5 grains in an ounce. A 125 grain bullet would be just over 1/4 ounce, while 325 grains would be nearly 3/4 of an ounce.