I've been lurking in this forum for months now, soaking up the knowledge and I am finally ready to purchase my first reloading press and accessories. I have settled on the Hornady LNL AP and plan to start with 9mm and 45acp for now. I have the Hornady New Dimension Dies with taper crimp for each caliber in my Midway cart, but am confused about the case mouth expander. Do I need the PTX in addition to the expander die that comes in the three die set? Is there any reason I should stay away from the combination bullet seat/taper crimp die when beginning reloading? Thank you in advance for your help. It never ceases to amaze me how helpful THR members can be.