I picked up a used RCBS Uniflow II earlier this year to use for smaller charge weights (<10 gr). The previous owner broke it in for me so I was able to hit the ground running. Earlier today, I filled the hopper 3/4 full of Universal, gave it a few taps with the handle of a screwdriver to settle things, and then threw a dozen to get into the groove (these were dumped back into the hopper). Once I had my groove on, I threw 50 as if I were filling cases (dumping to a container instead of back into the hopper). The results were:
min = 5.3
max = 5.7
range = 5.3-5.7
mean = 5.512
sd = 0.091
Frequency Table
Value, Frequency, %Occurrence
5.3, 1, 2.00
5.4, 13, 26.00
5.5, 17, 34.00
5.6, 17, 34.00
5.7, 2, 4.00
5.5 gr happened to be where I last set it.
I am in the "throw under and trickle up" camp and have also noticed that when I encounter resistance on the throw, the charge weight tends to be off. I typically throw those back into the hopper but did not do so this time. I measured the first 50, irrespective of whether they were good or questionable.