Something Else to Look Out for!
I am into my 65th year of handloading and, in that time I've made the usual mistakes and encountered the usual problems and have learned to pay close attention to minor details. Yesterday I came across a new-to-me issue:
Several years ago, a friend bought at auction a batch of cartridges put up by a commercial loader. He gave me the stuff he had no use for including 5 boxes of 7x57. I fired a box of them and the cartridges did not measure up to my accuracy/velocity standards so I shelved them and moved on to other projects. I noticed them the other day and decided to break them down to salvage the components for a load that performs better in my rifles. The existing cartridges consisted of new Winchester brass, unknown primer, 150 gr. Winchester power point bullet, and 45 gr. of a ball powder resembling W760. I pulled the bullets and dumped (discarded) the powder by inverting the cases and tapping two together to empty them. I then sat the empty cases in a loading block. At some point I glanced at the cases and noticed some dark spots on the inside case walls. Some of the powder had attached itself to the inside of the cases. I thought it was just a few kernels but I proceeded to scrape it off with an allen wrench. But it was not just a few kernels! The worst was 1.2 grs and the average was .35 grs.! If the brass had not been unfired and shiney I wouldn't have noticed it and would have reloaded it with a full charge on top of 1.2 gr. that was already in there. It's doubtful that, with my loads, the extra dab of powder would have created a major issue but it sure would have played mysterious hob with the extreme velocity spread.
Be careful out there; no detail is too small!
Thanks for the story. Good advice. 'Stuff' does happen.