You can use a new empty case to set your headspace and it would work, "BUT" several things could go wrong.

1. You take your rifle hunting and forget and leave "your" special ammunition at home and find out normal store bought ammo wont fit in your rifle.

2. You find over time your cases are getting hard to chamber and your decide to use a full length resizing die to bump the shoulder back only to find out your cases are now longer than when you started. You would need to lap your shell holder and remove a few thousandths to get the cases to chamber.

3. You sell the rifle to someone and he gets home and finds out his Remchester cartridges wont fit the rifle and he looks you up again and beats you to death with your old rifle.

Trust me, the shell holder below had .002 removed on a lathe and .001 removed by hand lapping in order to get a custom .270 to chamber a fully FL resized case to fit in the chamber. Just because yours truly wanted a tight chambered .270 rifle.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6943.jpg[/img]