RE: Roll crimp vs. Taper crimp
I also taper crimp on the ones that headspace off the front of the case, it the right way but I roll crimp everything else. Especially with slow burning pistol powders.
Even though a lot of people say I don't need to crimp for my bolt actions I still do. I have found I get better results with a good crimp and neck tension is not as important. There is a reason the factories all do it.