Get you a RCBS low primer warning buzzer for about $20-$25, buzz's when you are down to 4 or 5 primers. Fits right on top of the primer feed tube.
Same here. I've loaded a ton of .45ACp, and need to switch to the .223, and the .243WSSM.
I'm thinking about the case feeder as well just to eliminate one more step.
The only thing I found out, is that I have to lay out exactly 100 rounds, as thats all the primer tube will hold. There is no way to tell when you run out of primers without setting out 100 bullets, or 100 brass.