Like I've said before on here, I have about 1200 multiple fired cases I handloaded before knowing about the unsupported case problem. They were mixed mfr. I load for accuracy but have found that is usually near the top for my Glock 20 so most of my loads were at the top or nearly so. I probably loaded most cases 2-3 times. Maybe more. I never found one that had a bulge in all the operations of case prep, or a split, and watched on the last priming very carefully to find one. I never found one.
That being said, neither do I believe that my handloads were approaching the pressure of BB or DT loads. If it were me, and I wanted to load some stiff hard cast loads, I would purchase the bullets from DT, Cast Performance, or Beartooth (cheaper and shot good in my gun) and load my own within published recommendations.
I'd also use the barrel that supports the case the best and if it doesn't chamber correctly send it back. I have a Storm Lake barrel and have used it for a couple years and never had any issue with it not chambering or shooting my handloads if properly crimped with a Lee factory crimp die.
I've seen other posters talk about their 10mm loads for auto pistols on here which are 1 grain above "book" max for heavy bullets. Personally, I don't believe that is a good idea and may well be where problems or kabooms come from. Each to their own.
If you (rhetorical "you") need more juice in an auto pistol than 10mm provides, I believe the best alternative is a Desert Eagle, not trying to make the 10 into something it cannot safely become.
