Have two Hornady progressives now, one old Projector and newer LnL. Mostly use them for shorter runs.
Mostly use a Dillon 1050 for .45acp. Lots of experienced loaders will tell you to remove all cases when you have a stoppage or think you have some issue. I don't do that, just make damn sure there are no undercharged or overcharged case and move on. I never had a 550 but I understand its manually indexed so it would seem to me it may have a shorter learning curve. Visually check the charges or use some kind of powder check die! Most all the violent troubles come from charging problems, squibs or overloads. And like I saw mentioned above keep it clean, especially the primer feed. Setting off 80 or 100 primers will get your attention, you probably already use PPE, its even more important with a progressive.
