The Deluxe set includes the Carbide Factory crimp die. This die allows you to separate bullet seating from the crimping operation. It makes setup much easier and the die has the added feature of a carbide resizer that does a finishing sizing pass on the completed round. This final sizing guarantees that any case that passes through the die will freely and reliably chamber in any gun. The carbide and steel three die sets work fine when using a quality controlled source of brass, like cases fired only in your gun. More care is required when adjusting the bullet seat and crimp die, as seating and crimping occur simultaneously. Bullet diameter control is important when not using the factory crimp.