Originally Posted by idek
thanks again for continued replies. Here's another novice question. I see Lee makes 3-piece die sets and 4-piece. The set with 4 includes a carbide factory crimp die. As an ignorant beginner, I have no idea what that is. Is that 4th piece something I would probably want?
Short answer; yes.
If you use a 3-station turret or a single stage press, maybe not. But if you get a 4-station turret (like the Lee Classic Turret) you might as well.
If you get the 4-die set, you can use just the 3 dies if you want.
The main advantage I find with the 4-die set is that the dies are easier to adjust. Separating the bullet seating step from the crimping step makes the operation simpler.
Do a search on "FCD", "Lee FCD" and "Factory Crimp Die" and you will find a number of threads hotly debating the relative merits of the Lee Factory Crimp Die.
By the way, other die makers have comparable crimp dies. But Lee has a carbide ring in theirs that does a sizing of the cartridge (to ensure the cartridge still meets SAAMI diameter specifications after inserting the bullet and applying the crimp. Some find that useful, some, not so much and some find it hurts the cartridge. It all depends on your particular components.
My advice? If you think you might like a turret press (which I think you should consider getting) and will do continuous processing (as opposed to batch processing), get the 4-die set. As a set, it isn't that much more expensive and you can choose to use the 4th die or not use it with no penalty.