I used to weigh every single charge for everything.
It was very thorough !
I started realizing somewhere along the line that the only charges I was rejecting were the ones in the control and setup group- like Walkalong above.
Although, for my precision .308, I do reject a lot of them.... Mainly just because I can, and on those its more of a look before the scale even settles- and 9 out of 10 times I'm right.
As to when I made this transition ? It was probably somewhere right around the 6th caliber I started loading for- which was consequently when I started loading shotgun.
You don't get to weigh shotgun charges. Well, you could, but its not the same as dispensing powder from a measure in the metallic cartridge world.
That (shotgun loading) gave me the confidence to set the measure, and double check as Walkalong does above- and then carry on until the end of my run. If some little green commie wanted to sneak in and adjust my powder measure while I'm not looking..... he'd have to get past my cats first, and I don't give martians that much credit.
I dispense the charge into the case, examine that charge, seat a bullet, and move along.
Except for my really good .308 ..... Maybe one day.
For those of you who like Walkies "average" method above, you can dial in your powder measures using ten throws of powder into a medicine bottle or similar container. This is how I average out pistol throws- 10 charges of my 45 ACP w231 for example should be 51.0.... but I accept a margin of error as high as 51.9, an average of .1 over on each throw but one. If I dispense 10 charges and it weighs out less than 51.0, or more than 51.9, something is wrong- and I adjust it down and try again with another ten.
This WILL show you that your powder dispenser is throwing the right charge time after time. If you have a heavy scale, you could even do 100 charges if you felt so inclined.... I would lose count after ten- I can't count that high.