You do not need to FL resize, the whole idea behind these dies is to bump the shoulder 1-2 thou and resize the neck leaving the body unchanged. After firing the body of the case is formed to you rifle chamber, if you FL resize you will reset the whole case, this will obviate the entire reason you have a bushing bump die.
Select a bushing according to the use for the loaded case, for match shooting where you feed one at a time you use 2 thou of neck tension, for hunting or autoloading 4-5 thou of neck tension.
Most factory chambers allow the case to expand 5 thou after firing, most commercial dies are set to push the case back by 3 thou, hence if you FL resize you are under sizing your case by up to 2 thou more than the chambers actual size. In order to ensure you get close contact between the shell holder and your die, you need to use competition shell holders (they come as a set 2,4,6,8 thou thicker than a standard shell holder) you will also require a tool to accurately measure the distance from the base to shoulder (datum line) to ensure you are pushing it back by 1-2 thou only.
I have found the digital headspace gauge from Innovation Technologies invaluable
http://riflemansjournal.########.ca/2009/08/reloading-headspace.html
Lots of excellent articles at the above site
Good luck