357 Max

[Bullseye]

I crimp mine.  If your are using a powder such as WIN 296 you need to crimp it for proper iginition.

I crimp all my straight wall cases.  I have not tried, but I am not sure they would chamber without some kind of crimp since you expand the case mouth with the expanding die.

[boneguru]

as long as you don't exceed max pressure, I have alays preferred a taper to a roll. more consistent neck tension