So I started my friend reloading, and he's been practicing with me for about 6 months now. I started him off with a basic single stage press with everything he needed to reload safely. For the first couple of months he would come over and watch me reload as i explained what I was doing. It progressed to him helping me out with various steps of the reloading process, and eventually to him reloading by himself with me supervising. He's at the point now where he is profient at reloading, and ready to make an investment into some gear.
The main question is the press, and a single stage vs progressive. I know a lot of people prefer the single stage, even when they are experts because of the time needed for each round. He's not going to be making thousands of rounds, but because his weapons are limited in calibers I almost want to have him lean to the Dillon 550b vs the CO-AX. Has anyone been in this situation recently, or give me some general pros and cons? He is in the Marine Corps, and he is a very studious learner and pays attention even when I explain the same thing for the 100th time. Thanks in advance for the help.