How important is case weight segregation for 1000 yard target shooting?

Depends on who you ask. some well say very important others well say not.

It depends on the quality of the brass lots used. Some brands have terrible QC and cases will vary a bunch; these would require careful sorting and prep. Quality brass needs little. I have had good luck with Lapua .308 brass (admittedly from 20 years ago, others have had trouble with some Lapua lots in recent years).


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I have tried every brand of cheap and expensive brass there is and, I can tell you that ANY brand of brass can have some bad ones slip through.
I only use the 300 Win Mag for 1000yrd comp and even Winchester brass gets the job done with proper brass prep without sorting for weight. The most important factor is that your brass prep is consistent, once you find an accurate node even slight differences in powder weight/velocity will not effect accuracy dramatically. I debur flash holes, uniform neck thickness and neck tension and go shoot.
I actually measure capacity of water in my brass, some brass may weigh differently but still have the same internal capacity due to slight variations in the alloy used in the brass, not all the brass in a bag comes from the same production lot, they're a mix of different runs to make up a barrel.
If you use good quality brass like Norma, the only prep needed is to debur flash holes, everything else is always on the money.

Cheers.