let me start by saying that I have reloaded for many years 38 357 45acp 40sw just got a set of rcbs tc dies for my son in 380 set dies up using wnc and rp brass for slight belling of the case moth to start bullets all went well but anytime I try to slightly flair federal or blazer brass I can feel the expander ball go into the case then I feel a slight increase in press when it gets to the flairing portion and no matter how much flare I try to put on the case it crumples {bulges] the case only with federal or blazer brass the cases mice the same lenght and the case walls are all right at .10 thick I can feel considerable more tension when running the federal or bl. brass inti the expander die Any ideas as to why I,m having trouble only with fed. and blazer brass with the 380 only possibly brass being harder is the only thing I can come up with thanks jim