Pounds Mass vs. Force
To expand on rolschwarz's answer. The mass of the volume IS the force at 1G, or more accurately it is the attractive force exerted upon it by the earth's gravitational field. If the gravitational constant is different, say, on the moon or Mars, or Sol, then you would multiply that mass by the ratio of the "target" gravitational constant to the gravitational constant here on earth (which isn't even constant here on earth!). for instance, a pound of mass here on earth weighs 1 pound. on the moon, where the gravitational constant is 1/6th of earth's, the mass is still one pound, but the weight is only .16667lbs but it will retain the inertia of 1 pound of mass. The use of Pound for both Mass and Force is somewhat confusing to many people not accustomed to thinking about the force gravity exerts on everything. Without gravity, there is no weight, but there is ALWAYS mass. so .078 pounds of mass will weigh .078 pounds in a 1G field. Just try working out the forces acting on an object at any given point in time that is moving from one g field to another. That is when things get really interesting. That was what calculus was invented for! Really! Newton invented calculus in order to work out the laws of gravitation (as he understood them at the time).
On this point, the metric system actually makes a bit more sense, It uses different units for both force and mass, but of course it was formalized after Sir Newton's little epiphany with fresh produce. The pound system had been used for centuries prior to that and historical inertia is as real as physical inertia, it is just exerted in different planes so to speak...