I've reloaded and shot both Berrys & Xtremes in .380, 9mm, .357 SIG, 38 Special, .357 Mag, 40 S&W, 45 acp, 45 Colt, 44 Special & Mag without experiencing any real crimp-related issues...
These were all at "reasonable velocities": under 1,200 fps for the "regular" ones and well under 1,500 fps for the "high test" (a.k.a. heavy plate) varieties.
The real key to a good crimp, whether a taper or true roll crimp, is IMHO the proper expansion of the case prior to seating the bullet. This is, of course, highly dependant upon the bullet design and construction. Plated vs. Lead vs. Coated vs. FMJ, a cannelure (or not) all make a difference, as does the actual die used for the expansion (flare or belling, as you prefer) making a difference as well. The application of the crimp itself (if done with the seating die or with a dedicated crimp die, i.e., a LEE FCD or a collet-style die) can make a big difference as well, but...
Again, IMHO it is improper (as in OVER-)expansion of the case that typically causes the most serious problems. In many (if not MOST?) loads the case tension alone should provide the majority of the "grip" on the bullet, the Magnum calibers loaded HOT being an obvious exception. Images of cases with obvious belling (somebody once asked if someone was "making trumpets?") require so much or a taper crimp to remove it is a wonder they will chamber at all, or, in the case (OK, in the "instance") of calibers that index on the case mouth, whether reliable and consistant primer strikes can even be expected...?
Shaving of lead, coating or even copper from jackets and plated bullets clearly indicates insufficient expansion, and can result in poor performance, but bullets that drop halfway into a funnel cause problems as well.
This all has more to do with achieving consistant reliability and accuracy vs. just making ammunition that goes BANG! Proper expansion is not always easy to tie down but is well worth the time (and sometimes the frustration) that is necessary to insure.
Cheers!
