I've read enough to know the different applications of roll vs taper crimps, however, I am (without sounding dumb) still lost as to how to spot the difference. I mean, a heavy taper crimp will look just like a roll crimp, right? I've been using Lee dies all this time, thinking that, say, my .357Mag dies (seating/crimping die) applied taper crimp. Today I got to use, for the first time, the Lee Factory Crimp die, which is supposedly a roll crimp die, and the crimp looks just like the crimp from the seating die.
How does one tell the difference, or what difference is there to the internal crimping surface?