So your brass has been de-primed and polished. You are now ready to re-prime & re-size the casing. In my particular case, since I de-prime and then tumble, small bits of the polishing media can become stuck in the primer pocket. The Lee resizing die also has a depriming rod in it. This will remove the polishing media and allow your fresh primer to seat correctly in the pocket.
The first thing you want to do is to lube your cases. Carbide die sets are supposed to eliminate the need for lubrication. I have found that it is much easier on my arm when pulling the handle for the cases to be lubed. Lee makes a tube of case lube that comes with their anniversary kit. It works, but you will spend a lot of time individually lubing cases. I use One Shot as shown in the picture above. Spray some on your cases and in my case I spray the inside of the sizing die. The added benefit is that your equipment is less stressed.
Once the lube has dried and you have your primers loaded into the primer feed, it's time start feeding cases. This is as good a time as any to visually inspect your cases to look for defects that would be cause for you to reject the case. Split cases and creases at the slug end of the case are common things I've found. Reject those out of hand.
If you feel that it is difficult to seat a primer, stop. You might have encountered a case that was Berdan primed. If you see two holes instead of one as you look into the case it is Berdan primed and must be thrown away. Of course you could also have just a very tight primer pocket. Either way, closely inspect the pocket and if in doubt, chuck the offending case in your brass recycle pile.
Now that you have a supply of primed cases, you should check their length to be in tolerance. This is where your load data book will help you. The book has specific loads for specific bullets as well as critical dimensions for the particular calbier you're reloading. Since I reload 9mm the length of my cartridge should be .754 inches. It never hurts to check your diameters both at the front and back of the cartridge as well. Cartridges that are out of spec will not fit into the chamber properly.
Next time. I'll discuss deburring and charging the round.