Originally Posted by BE Mike

I have a 550 and 650. The advantages of the 650 are the extra hole for powder checker, self-indexing and the case feeder. It's faster than the 550, no doubt. The only drawback is if you load with powder that nearly fills the case, I find the 650 to be a little bit "jerky" and a little powder could come out the top of cases. I've tried just about every do dad and trick to smooth the operation, but the cases still tend to jerk into position.