The only time I use the Lyman M die is when I load my 225215 Lyman 55 gr FP gas checked cast bullets.
The 40 gr ballistic tips designs ,Vmax,NoslerBT, Sierra BlitzKing are usually boat tails and are a breeze to seat in the Hornet case that's chamfered.
The 35 gr VMax and bullets that are 30-35 grain HPFB designs from Berger,Barnes Grenades,Speer TNT's and other flat base bullets can cause problems IF you don't take the time to chamfer or use a seater that has a floating bullet to case neck sliding sleeve,bushing, to align the bullet with the case.
The mandrel in the Lee Collet as sent from the factory is just the right size for the Hornet I shoot and the seater that comes with the deluxe set works very well, no crushed cases to date sizing and seating for any of the above mentioned bullets.
The only only Hornet case I have ever crushed was when adjusting the crimping feature of my Lee seater die (found out later crimping gave poor results) while seating cast bullets and it wasn't equipment problem but rather "pilot error"!