Thank you Keith. So, is the general suggestion in this case to reduce the load by 10% and then work yourself up?
BillK
The 10% reduction seems to be a generally accepted rule. But as Mike says, there are weaker action types that might fail or sustain damage before some pressure signs appear. Then there may be other factors that could come into play, such as problems that arise when powder volume reductions are made with some powders that already occupy a small volume of the case. There are certain powders such as WW 296 and H 100 that may cause pressure excursions when loads are reduced too much. With some loads, performance may vary due to position of the powder in the case, and sometimes this is prevented by using fillers such as Dacron, for example. In those instances, it it probably wise to stick to known and tested loads using the recommended components.
Fortunately, most reloading data has become more cautious and conservative over time, likely due to liability concerns. And it pays to consult multiple sources to confirm the loading data you are using is safe. Typically, there is a certain margin of safety built into loading data, and no legitimate reloading manual is going to recommend loads that go to the extreme of blowing up commonly used firearms. The internet has made finding load data much easier than in the past, but errors and misinformation can be posted online, so one should always confirm that a new load is legitimate and safe. Anyone on the internet can pose as an expert, so take time to verify. I've known some guys who start at maximum, and work their way up until they see pressure signs. Veering off the road and speeding into the weeds is just asking for trouble. I'm happy with a safe reasonable load that gives me the best accuracy. I've killed enough game with a lowly roundball moving roughly 1800 fps out of a flintlock to know I don't need barrel melting speed.
