I'm confused, why then exactly did you buy a .357 Magnum revolver? Why not go with a much cheaper 442, 642, etc. if +P is all you are going to shoot anyway? I shoot FULL house magnums from my 3 1/16" SP101 all the time (admittedly, at the range with hearing protection) and have no issues. That is the reason I went with the slightly longer barrel in the SP, I wanted to shoot MAGNUMS out of a MAGNUM revolver. These same loads hurt out of my 2 1/2" Model 19 with factory stocks. So, the cute little 19 stays home and the SP, Speed Six, Models 27&28, etc., go to the range. I say find a mid-range .357 140ish grain load that you can find and actually buy shooting quantities of and that is accurate in your gun. Any of the quality name brands should do the job. Save the .38s for practice and remember to clean the rings from the chambers.