I can't stress enough the value of taking your time, and making sure of each load. The 550 is a fine unit, but it takes a bit of practice. I've had two squib loads, where the powder was missing. Lucky for me, the next round wouldn't chamber, on both occassions. Pounding out stuck bullets is no fun. Of course, being aware of every round being fired, will prevent a real disaster. Totally my fault. Now I do a visual for powder on every round. Only other problems have been flipped primers, and missing primers. The missing primers are very easy to spot, when you have to disassemble everything to clean out the powder. If the Dillon has a short coming, it's the primer feed.