Hi:
Planning on entering Reloading.
What is the differences in a "Roll" and a "Taper" crimp?
Thanks,
Jimmy

You can see it illustrated in this photo (compare the case mouths - firm roll crimps on the left three, firm tapers on the two on the right):



A roll crimp "rolls" the end of the case into the bullet. A taper crimp squeezes the bullet in a gradual taper of the case.

You really need to get an entry level reloading book which will discuss lots of basics like this. Lee's Modern Reloading (2nd Ed.), while not perfect, isn't a bad place to start.

jimmyj read your loading manuals regarding taper crimp for 45acp. It headspaces on the case mouth rather than the case rim. Spec is 0.473" at the case mouth. If you are using moon clips for a revolver the loading practice is the same, but not an issue.
measure everything you can, then double check it.

Roll or Taper crimp?
Back in the 70's I had just started reloading the .45 ACP. I needed a TAPER CRIMP for the .45 ACP. The gun shop did not have one in stock. The sales person brought me an RCBS Sizer Die without the decapping assembly.
After removing the decapping assembly and re-adjusting the die it works as a TAPER CRIMP DIE!