I use a Lee Classic Turret press. I size and prime in a separate step and use the four die positions as follows:
Position 1 – Lee Drum Powder Measure
Position 2 – RCBS Powder Check Die
Position 3 – Lee Bullet Seating Die
Position 4 - Lee Factory Crimp Die
I load 357 mag with 4.3 grains of 231 with a 158-grain coated bullet. I’ve loaded over 10,000 of these in the last year or so and never had a problem until now. It’s a nice and accurate target load.
On my first batch of rounds after setup all was going well when suddenly, the powder check die was showing light charges. I always look inside the case with a mirror before seating the bullet and looked OK. There was powder. It’s very hard to judge variations in charge with such a tall dark case with light charges. Sure enough, upon weighting the charges it was throwing half charges. It appears that the powder measure was somehow damaged in the move. I will be sending it back to Lee for repair.
If the RCBS Powder Check Die hadn’t caught the light charges, I could have produced a batch of squibs. The consequences could have been disastrous at the worst, inconvenient at the best.
The lesson learned is that any equipment can fall, even equipment that has reliably produced thousands of rounds in the past. It is good reloading practice to make sure that the charge is right before seating the bullet. In my case I double check. First with the powder check die and then a visual check. In my case the visual check would have failed. Visual checks are often OK alone if the powder fills a good part of the case and the case is short so that you can see clearly inside. It was never a problem with 45 ACP. Neither applies in my case with the 357 mag making a backup check essential.
I was lucky.