Looks like everyone else has hit most of the extras you need, so I’ll just touch on a couple of safety issues when loading on a progressive press, especially one with manual advancement such as the 550.
1. Don’t let yourself get distracted while using a progressive. Loss of concentration could result in a case with a double charge or one with no charge. Always complete the cycle you are currently working on. If you’re reloading and the wife calls out that dinner is ready, don’t stop in the middle of a cycle. Run the press until all brass in the shell plate has been run to completion.
2. When I started loading for CAS with the volume of ammunition that I was using, I became concerned that the probability of an error was increasing. Because of that, I turned my high volume reloading into a two stage process (until I purchased my first 650). This two stage process was necessitated by the fact that the 550 is only a 4 station tool head. The way I set up was as follows:
First Station – Deprime, Resize, PrimeAfter running all ammo through this configuration, I would change to a tool head that had only the crimping die and re-run all ammo through the crimp die. You could keep this a single run process if you use a combination seat/crimp die, but I prefer to use a separate crimping die.
Second Station – Case belling and Powder Charge
Third Station – RCBS Powder Check Die or Lockout Die (this differs from a
Fourth Station – Bullet Seating
The Lockout Die or the Powder Check Die allow a mechanical or visual confirmation of the powder charge. I’m sure most reloaders will think this an unnecessary step, but powder bridging (resulting in a reduced or no charge) can occur as can a mechanical malfunction that is not readily obvious. Failure to advance the shell plate can lead to double charging a case. For these reasons, I felt this two stage process was worth the extra time involved.
3. While unlikely to occur while loading jacketed bullets, there is a malfunction that can occur while reloading lead bullets. I know of at least one reported case of this that was caught at the time and there is speculation that this may be the culprit in a few blown up guns. When loading lead bullets, the bullet lube will build up inside the seating die. On the one reported occasion, when transferring the completed ammunition to bullet boxes, the operator found one case with no bullet and the powder had been dumped into the ammo collection tray. At first, he thought he had just missed putting a bullet on one round but he decided to weigh all of the loaded rounds. He found one case that had two bullets in it. What had happened was that the lube had built up inside the seating die. When he placed a bullet on the case and ran it into the seating die, the bullet became stuck in the die and he did not notice it when he cycled the machine. When he placed the bullet on the next case and ran it into the die, both bullets were pressed into the case. Had this round been fired, it most likely would have resulted in a blown up gun as he would have had 500 grains of lead on top of a powder charge intended for 250 grains of lead. Pressures would have shot off the chart. This scenario is unlikely to occur with auto pistol rounds as the case is not long enough to hold two bullets plus the powder charge, but could occur in some of the longer revolver rounds. This potential problem is not limited to the 550 press. This could occur with any progressive press. For that matter, it could occur with a single stage press but you'd pretty much have to be asleep at the wheel to not notice. The moral of this story is should you ever find a case in your completed ammo tray with no bullet, don’t assume you just missed placing a bullet on one case. Inspect all ammunition to eliminate this “double bullet” scenario.
You’ve made a great decision going with the Dillon machine. The 550 is one of the most versatile reloading presses out there and Dillon is outstanding to work with should you ever have a problem. It will give you years of service without problem. Mine is over 20 years old and the only part that ever broke was one of the return springs on the powder measure. Have fun and shoot more.:biggrin2: