What process do you do with new brass?

[NapalmCheese]

I took a sample of 10 from a case of 250 Starline 5.56 brass.

Case length varied from 1.746 to 1.752. Kinda disappointed. I can’t trim the short ones, and the variance is worse than when I process once fired.

I gotta figure out what to do here.

It's Starline, not Lapua. You paid $0.25 a piece for your Starline brass instead of $0.60 a piece for lapua. You literally paid less than half what you would have if you'd bought better brass. That savings comes from somewhere.

Min length for .223 is 1.740, max is 1.760. You could trim them all.

Load them all light, fire once, minimally resize, trim, and carry on.

Or just don't worry about it.

[ar15barrels]

Load and shoot.
I don't think I have ever seen a chamber that 1.752" would be too long for.
Worry about them when they are approaching 1.760".
If you are that kind of worrier, check your actual chamber's max case length.
Many will take 1.77" no problem.

[divingin]

Quality brass is generally annealed as one of the last steps before packaging. In shipping, some necks may get dinged, dented or slightly crushed, which is why many say to run it through a sizer - to get the expander ball to return the neck to round.

You can uniform primer pockets, sort cases by weight, debur flash holes, trim to length, turn necks to uniform thickness. Is all that necessary? Probably not, though that depends on what you plan to do with the brass. Hardcore precision competitors will do all that (and probably more); I generally just visually inspect case mouths for deformation, and if there is none, I load and shoot.