I have an original OLHAUS beam scale that belonged to my grandfather that’s at least 40 years old that I trust. I bought a gem pro 250 but was not impressed. I found a used Sartorius GD503 off Ebay that I use now with a dandy electronic trickler that measures to the kernel.
This is one of several things I changed over the last year and I believe it helped. I’m pretty confident of my load when I believe I’m only plus or minus 1 kernel of powder from case to case.