With HP-38 I've had some inconsistent ignition (clear differences in report and recoil including a couple squibs) in cold weather and the accuracy seems to come apart a bit when it's below ~ 40°. I haven't been able to put my finger on the exact issue but it seems to be a developing pattern with mid range .38 loads (I'm suspecting lower pressure loads + cold temps). I need to mess with it this winter and see If I can iron it out with a primer change or something. So far it only happens in cold weather though. And only with .38 special, my mid-range .357 mag loads with HP-38 seem to work fine.