Some cartridges require 2 forming stages to keep from collapsing and ruining brass when trying to swage in one step - and the .33WCF is one of those. This intermediate step is called the "Form" stage - and coincidentally, this "Form" step creates a .38-56WCF case, which is another member of the same case "family" as .33WCF and .45-70. Note that the brass sticks out a bit from this die - nothing is done with the excess at this time.
This intermediate case is then run all the way up into the "Trim" die
Here, the excess length is filed away. The die is hardened so a file does no damage! (BTW, older RCBS dies are dated! You can see that I ordered these back in 1977.)
The case mouth is now deburred and chamfered:
The 3 cases: .45-70 (Left), .38-56 WCF (Center), .33 WCF (Right)