Originally Posted by
harry mac
It does matter. When a case is fired, it swells out to fill the chamber, this often has the side effect of shortening the case. If you only neck size, you won't squeeze enough of the case back into shape to make it "grow" again.
measure all the cases and trim them all to the shortest length. At least then, you'll start with uniform case length.
A few thou short of minimum is no bother. They will grow eventually, but neck sizing minimises movement of the brass.