Couple variable I looked at when I loaded my 336 30/30 actively. (until it was stolen
)
For hunting ammo, I would always use a bullet that had a cannelure, and always crimped to some degree depending on the load. WW 748 type ball propellants that had a lower load density than stick propellants got a higher level of crimp. Compressed IMR stick propellant loads got much less, as the charge prevented any possible setback and it seemed the crimp did more to keep it seated, than prevent setback.
My 20 plus year old RCBS dies seem to have a pretty big expander, and neck tension always seemed weak. When I started loading 30/30 and all other calibers, Lee FCD's were not around so for me it was roll crimp or nothing. Roll crimping was also done in either one or two steps depending on amount. If light I could seat and crimp at one time, but if heavy, it was seat all rounds, them back of the seater stem and crimp. It's real easy to collapse the shoulder if not careful.
Using cast bullet loads, I would crimp lightly, or not at all because I fed them usually one or two at a time, and the .310-.311" bullet diameter added a lot of neck tension. Just a side note, but I had great luck using properly sized cast bullets in my micro grooved 336, contrary to what others have reported.