Re: ? on BC
BC and pressures have, essentially, nothing to do with one another. Totally different matters. However, some feature that may contribute to the changes in BC, could also affect pressures; bearing surface, ogive radius, rifling engagement at a given OAl, that sort of thing. Bottom line here is, you changed a component, which means starting from scratch where the load is concerned. Different ogive shape, jacket thickness or core hardness, all this goes into the mix. But those are the issues that have created the pressure problem, not the BC per se.