Lyman 55 - the Gold Standard. It mounts onto their turret press.
Lee Perfect Powder Measure, which now gets more use. A STEAL at $20, including a bracket to attach it to your bench. The Lyman bracket alone costs more. I am entirely pleased with this Lee product for rifle loads (223 & 308). It has a LOT more capacity than those require.
Hint: Remove the drop tube from the LPPM and the measure will screw into Lee rifle powder charging die.