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Annealing works because it sets the tension of the brass to zero (simplistically speaking) That same brass, then acts uniformly when fired (if sorted for volume ,same brand,same neck-thickness etc). ...

Crimping introduces another variable, it is worth trying though,on already uniform-brass, where yr struggling with a powder or accuracy. There are lots of interesting discussions around crimping, on...

Might not have got to the Moon without OCD....

As mentioned above, I find case-neck-tension can be a huge variable in the pressure-variable part of the equation. You need to get your brass as consistently-equal as possible if you are going for...