I went thru and weighed, as meticulously as I could w/ my Redding #2 scale (magnifying glass set up to increase visual resolution of the pointer scale), 50 charges thrown by my Redding BR-30 w/ the full Sinclair kit. I also did the same for my Lee Perfect Powder Measure.
I did this for 50 *consecutive* throws, not throwing any ones that felt 'off' back. I know at least w/ the BR-30, if a throw hangs up bad it'll generally be light, and the next one (maybe two) will be heavy. But I didn't figure it was fair to pick and choose which throws I took and which I didn't; I wanted to see how well the measures threw mounted say... on a progressive press where I most likely wouldn't have the ability to feel a bad throw.
Long story short, they both threw w/ a 0.6gr extreme spread. If I'd picked and chose, the spread would have been much smaller, but that wouldn't have been consistent w/ the object of the test. I'd honestly thought both were much better than that, must have been selective memory or something of when I'd been throwing and weighing scales. When I got down to actually weighing and writing down every single throw... the results weren't all that impressive. FWIW, I believe there are people who have run similar tests on RCBS Uniflow and Harrell's meters w/ Varget and I've ran a similar test w/ N-140 on my Dillon 550 (similar short extruded grain) The stuff just doesn't meter all that well in the absolute sense.
That said... if the load is at a sweet spot or 'node'... throwing still seems to work pretty well, at least for what I'm shooting (Highpower); thrown charges shot along weighed in a .308 Win from 300 to 1000yds hasn't yet revealed a huge advantage to weighing, at least not in my score in F-class. Maybe a more experienced shooter w/ a more accurate rig would benefit from the advantage; so far I'm kind of on the fence as to whether I really need to do it (weigh charges). For my absolute 100% confidence match rounds, I do just to tighten the mental nut a little bit. For my practice rounds... I have better things to do that putz around weighing every charge.
YMMV,
Monte