Funny you should say that.
Out of curiosity, I weighed an entire tin of JSB's yesterday... only to find that all 501(!) pellets were within a range of 8.38 and 8.52 grain. Which in itself is reassuring enough, and which indicates why, in order to get better results, there is no need to weigh pellets from a good batch whatsoever.
But I would not do this because I want to shoot better.
Trust me, not practicing shooting for ten years does wonders for your inability to shoot properly... so in my case, the time would be better spent practicing rather than drinking beer. Or weighing pellets. It's just that it's very hard to practice when it is pitch-dark.
Then why the bleep would I do it at all?
Because I am insatiably curious for information for which there is no apparent use. I am a guy who would use (and actually has used) his lab scale to determine the average weight of a housefly.
Turns out this was a fairly useless excercise, because it turns out that the average adult housefly weighs APPROXIMATELY three times the error margin of my lab scale: the margin of error is specified at 0.004 grams, and if I remember correctly, the average number I came up with from a batch of 17 dead houseflies is 0.014 grams.
Of course, the tin of Exacts wasn't the only tin I went through. I also took a random pick of 25 pellets from a tin of H&N FTTs, and the result was rather shocking, as the extremes were more than a grain apart... 8.18 to 9.23.
Whether this is the cause, let alone the single cause, of why I can't hit the broad side of a barn with these pellets remains unanswered, but it did make me curious. Hence the question.
The simple answer would've been 'dump them and take the loss', which is what I do anyway... ok, they're in the stack of pellets to use for practicing standers at closer distances.
But I was one of kids who always wanted to know why, and spent many a night not watching the telly, but trying to figure stuff out (and blowing a few fuses in the process). And that kid is still in there.
IF I would ever decide to weigh pellets for a comp, I would only do so to silence the voices in my head, because I have now empirically proven that there is no physiological reason for weighing your pellets.