I say go to the experienced people when you have a problem. A while back I said I was going to convert my 357Mag cadet Martini to Max. Well, I done it, shot it today, and got a problem. 1st load was 158gr Hornady HPXTP,21gr IMR 4227, CCI 400 primer. Shot well, no sign of trouble. 2nd load was 180gr Hornady HPXTP, 18.5gr IMR 4227, CCI 400. Two of the three cartridges had punctured primers. 1st mistake was that my book said Hodgdon, not IMR, altho the Hodgdon is only supposed to be slightly slower. I am wide open to ideas and suggestions. I'm thinking maybe something slightly slower? There were no pressure signs on the other cases. Over 40 years reloading and never had something like this happen. Goatwhiskers the Elder