As others have ably posted, the dippers work just fine and when properly used give very consistent results, but the sliding chart is most always not 'accurate', most often giving a lighter load than a reloader wants. (read lawyer-ese for CYA)
I have used the dippers, the Lee Perfect powder dispenser and mostly now the Auto-Pro disk. For batch reloading IMHO the Perfect measure is faster to use since you don't need a funnel to avoid spill over.
For my use, I load low-mid range plinking ammo and would feel well served using any of the methods or dispenser styles. Pistol reloading 'usually' involves higher volumes of ammo, and I have no need for 'gnat's eyelash' levels of charge weight 'accuracy'.
I have used the dippers, the Lee Perfect powder dispenser and mostly now the Auto-Pro disk. For batch reloading IMHO the Perfect measure is faster to use since you don't need a funnel to avoid spill over.
For my use, I load low-mid range plinking ammo and would feel well served using any of the methods or dispenser styles. Pistol reloading 'usually' involves higher volumes of ammo, and I have no need for 'gnat's eyelash' levels of charge weight 'accuracy'.