Varmint hunting places extreme demands on bullet performance. such bullets must be exceptionally accurate to hit small targets, lightly constructed to provide explosive expansion while minimizing ricochets, and lightweight to obtain high velocities with flat trajectories.
sierra blitzking bullets are the standard against which other brands are measured.
6mm .243 caliber blitzking
sectional density: .145
ballistic coefficients: .182 @ 2500 fps and above .193 between 2500 and 1800 fps .205 @ 1800 fps and below
note: these are component bullets, not loaded ammunition.