The Lock-N-Load powder measure offers the most flexible operation and the widest range of any powder measure. Go from.5 grain to 265 grains by simply changing rotor and inserts. Use one Lock-N-Load Powder Measure for reloading everything from small pistol cartridges to large magnum rifle cartridges. To change metering inserts, just push the Lock-N-Load insert release button and insert another metering insert. With only.002" clearance between the drum and rotor, it's the tightest in the industry for a standard measure. This tight tolerance helps eliminate powder binding between the frame and drum, delivering smooth function with all types of propellantextruded or ball.