Just got into a new cartridge and decided to load it on my very early 550. I like to think of myself as a Dillon beta tester since as soon as I ran into a problem they had just run into it themselves. I don't recall the comp shooter they sponsored but I am glad he got their bugs worked out. Thanks to his efforts and Dillon's peerless customer service I never missed a match due to loader issues; I was shooting 2-3 matches per month plus practice.
My new cartridge is the 380. Got new Dillon dies & shellplate and had it up and running in about an hour. Auto prime mechanism changeover was a bit troublesome and I got brain gas adjusting the powder measure so it took me awhile to get everything just right. Been awhile! My 550 went into retirement for over ten years and came out a couple of years ago when I couldn't stand the price of factory ammo any more. Pulled the cover off and it was set up for 45acp so away I went. Today it took a little over 20 minutes to load 100 rds. Those little 380's are a bit small for my clumsy fingers.