I don't think that's correct. The shell holder touches the bottom of the die. It doesn't fit inside the die and can't go any farther toward the shoulder than the bottom of the die no matter how far in you turn the die. The die is not compressable at force levels generated by a manually operated press. If the die is designed to be set up at contact, which all of the ones I have are, it is physically impossible to size the brass too short for SAAMI specs. If it is too short for the chamber it is because the chamber is too long.
Try an experiment. Screw the die in till you get firm contact with the shell holder. Size a case. Measure the base to shoulder distance. Screw the die in two full turns more. Size another case, the two cases will be the same base to shoulder distance.
Since the case headspaces off of the shoulder, you can easily have excessive headspace. Someone correct me if I'm wrong, but I think anything over about .005 is considered loose........Rich[/QUOTE]
The only way to get excessive headspace is if the chamber is out of spec long or the die is out of spec short. There is the possibility that the chamber it self has excessive headspace which is readily determined by using a no-go gage. If that is the case it would be possible to have the brass too short for the chamber but still within specification. In such a case it would also be bad to shoot factory ammo in that rifle.
What am I missing here? [/QUOTE]
Fitch
You are "assuming" that the die screwed down until it touches the shellholder actually matches your chamber. That is the first mistake!
Like Bart said, you either have to use some type of precison mike or bump gauge to measure your fired cases on the shoulder. From that you only want to bump back .0015-.002.
Many times you can screw the die all the way down and get .015 or more push back which will lead to case head separation.
There are variances in shell holder heights, dies and such that you cannot just screw the dies down, resize and expect long case life.
I have also seen dies that had to have .020 ground off the bottom of the die to get proper sizing.
FL sizing is sizing the body AND moving the shoulder back some, the only question is how far pushing it back.
Different mftr of the dies have different thread pitchs and a 1/4 turn does not equal a quarter turn with the next die.
Get in the habit of measuring the shoulder, starting high of the shoulder and coming down very little at a time until you get the no more than .002 shoulder push. Forget the mftrs instructions, they are not designed for long brass life.
BH