I recently got a Cimarron 1873 .357 levergun and cast some NOE 358-135 FN bullets for it.
Most every revolver bullet has had a pretty clear crimp groove but this one does not. The only groove is the lube groove and I believe the crimp goes in front of the driving band. The WFN bullets seem to have the same set up.
If I understand it, seat so the driving band is buried below the case neck just enough to fold the crimp in front of it.
Or are you roll crimping into the band itself? That seems odd but it would probably curb bullets getting set back with recoil.
the other parameters are of course getting the cartridges to be long enough but not too long to cycle and feed from the magazine with hiccups.
*Disclaimer, I am very sleepy and about to go to bed so my responses will be delayed any about 8 hours.