Thought I would share my recent experience with these products.
After testing my 115FMJ 9mm 4.3 gr reloads sucessfully this weekend I decided to go into production and make 250 rounds.
I felt the 4.3 was a little light so worked up the load to 4.5gr.
After zeroing out the Lee Scales I moved the grain slide upto 4.5 grains and threw out 3 sets of 2 loads form the Lee Perfect powder (adjusting each time to get 4.5 gr).
I loaded 250 rounds and checked every 10th throw on the Lee scale, all but 3 of my test\check loads were 4.5 exact, I got a couple of 4.3 and mabey a 4.6 in there.
I was very impressed with the consistancy and the check every 10th load really just serves as peace of mind for the reloader and its quick to do anyway.
The only things I did was
a) kept the hopper above 1/2 way mark
b) be consistant with the speed and movement when operating the dispensing lever
Im not sure if there is such a thing as set and forget in reloading but the Lee PPM must come close.