What powder? I use the Perfect for 4064 and it is +- 0.1 after about 20 throws. In my experience with the Perfect, it is necessary to flick the handle after the throw. Not real hard just a light flick with your index finger. I also store the measure with a dryer sheet to prevent static from hanging the powder up.
From what I have read, you can't do much better than the Perfect for the long stick powders. I did not like the cheap plastic feeling of the Perfect, but after some research I decided to buy several and leave them set for each load. That saves more time than anything else. If you want cheap and consistent, short throw into the pan then trickle up. I think the only way you are going to throw problem powders exact is to spend the money on one of the automatic digital dispensers.