New user to Quickload and I've noticed that there are 5 different choices for 300 Win Mag:

300 Win. Mag.(@)
300 Win. Mag.(F)
300 Win. Mag.(N)
300 Win. Mag.(R)
300 Win. Mag.(W)

I'm assuming these represent the different brass manufacturs (Federal, Norma, Remington, Winchester)? What's the @ sign?

Thank you for posting that.
That never occurred to me.

Quickload Maximum Case Capacity, overflow Grains H2O
@ 91.50
F 92.00
N 95.50
R 88.00
W 93.8

I just went and measured some of my brass:
@ na
F 87.7
N na
R 89.4
W 91.2

What does it all mean?
The brass is different between brands, but not very repeatable.

Lapua = 94.2 grs. of H20