For the first two decades I reloaded handgun rounds, I was using a single stage press and everything was loaded with either Bullseye or Unique. I used an RCBS powder measure and it gave me good consistent drops with both powders. I finally picked up a Pacific Pistol Powder Measure, that came complete with a stand to mount on your bench, and an assortment of bushings you used to adjust your powder charges with. Using a locking block to hold my primed cases, the Pacific was the best measure I ever used for a single stage. If you are going to look for a used powder measure, check for an RCBS with both barrel attachments. That way you can use it for hanguns and rifles down the road. The Pacific works great for handgun loads, but ONLY handgun loads.
When I got my first progressive press about 20 years ago, I could not get a consistent drop with either Bullseye or Unique, and that was driving me nuts. When I called Dillon they suggested I find a ball powder to use with their powder measure. I use Accurate Arms (Western Powder) no. 2, 5, 7 and 9 for all of my handgun loads now, and always get an extremely consistent powder drop.
I know powder is hard to find now, but if changing to another measure does not solve things for you, you may simply need to find a ball powder to work with.