I am of the understanding that a bullet with a G7 Ballistic Coefficient of .344 will have a G1 Ballistic Coefficient of .69. It seems that at certain "normal" velocities, the Coefficient of Projectile Retardation corresponding to the G7 Drag Curve is approximately twice that of the G1 Drag Curve. Does anyone here know what velocity range is used to find this ratio?

You might want to read this topic: Ballistic coefficient conversion I don't know that there is a "velocity range" -- mathematically it's only valid at a single velocity (other velocities would give different coefficients).