I owned a Dillon 650 with a case feeder and did not like it. It was to automatic and complicated, so I sold it and purchased a square deal B. At the time my purchase decision was between the 550 and the SDB. I like the auto indexing and was not loading rifle, so I purchased the SDB. The machine works fine, but the force to cycle the machine and seat the primer is much greater than the 650. I use Hornady one shot lube and put one of Adam's balls on the press, which helps, but it still is not like the 650. I was considering purchasing the 550, if it had the same mechanical advantage as the 650. In other words ease of cycling the machine. After following the red vs blue wars I decided that auto indexing is not necessary for me. I shoot two hundred rounds a month unless I have a gun class. I am getting on in years, in fact I had to sign up for Medicare this year. I may not be as old as Jack, but the body isn't what it used to be. I enjoy loading and shooting and want to continue as long as I can. Jack is my role model in that respect. Wanna kill these ads? We can help!