Re: Necking down from 6.5 to 6mm
The "donut" is a wierd thing. I am a little confused by that theory myself, so it would be nice to hear some other opinions.
I heard that the donut is created when necking up brass, which would make more sense (to me anyway). Makes sense that the neck shoulder junction wouldn't want to expand fully or as easily as the neck itself does, and therefore would be a smaller ID once the neck up has been done.
I am failing to visualize how necking down would create a smaller ID at the shoulder junction (based on the same logic of that portion not wanting to move as easily).
FWIW, I just neck size partially with a neck die (not the full length of the neck) and seat bullets and fire. They chamber just a little snug, because there is now a "false shoulder" where the neck die stopped sizing down, but it's only snug for that first fireing (unless it's a really warm load).
I'd like to hear other opinions myself.
Aim small = Miss small