8-12 grains??? Holy Cow! I bought black box prepped Nosler brass during a spring sale. I weighed 25 random cases today, all within 1.5gr.The "custom" brass is sorted by weight, chamfered, debur flash holes, etc......
It is completely prepped and ready to load as is.
Competition reloading short cut for foundation of consistent ammo.
Unless you plan on loading up for a serious rifle shoot, or perfect as possible ammo for those tight 700yrd + groups, it's not likely a noticeable difference.
Especially if you buy at least 100 pieces of brass and sort and prep them properly yourself.
Most don't sort brass to all weigh the same. And if it is weighed, it really only needs to be within around 8-12gr. of each other to be close enough.