I roll crimp all my 9.3x62mm rounds when there is a cannelure, likewise my .303.

I've had good results with my ZKW465 Hornet with the Lee factory crimp dies... but again only crimp when there is a cannelure in the bullet.

In the case of the Hornet, the Winchester 40gr JHP's were noticeably more accurate when crimped in place... I'd say that in such a small case the crimp allows pressure to build up to a consistent level before the bullet releases from the case.