i have been working up 3 different powders for my 300 wby mk v action 30 inch barrel. im using h4831sc....imr7828....Hercules reloder22. max loads that i have done so far are 75gr...78gr....76gr. respectively. i am testing 220gr. sierra hpbt mk's. im worried about missing max limit by not catching high pressure signs before its too late. i have taken some pics of the case heads so you can look at them and tell me if im getting too close. primers appear to be getting flattened but bolt opens easily and no extractor marks...at least i cant see any. primers appear a bit cratered also. federal 215 magnum primers are being used. i know what im looking for but im not seeing it yet and the manuals i have are maxed out....should i continue till i see something drastic.