.6 cc equals how many grains?

Answer 1

cc is a measure of volume, grain is a measure of mass. You need to define a density before the Question makes any sense.

Answer 2

To convert from cubic centimeters (cc) to grains, you need to know the density of the substance in question. Once you have the substance's density, you can use the formula: 1 cc = (density in grains per cc) grains. Without the density information, a direct conversion is not possible.