What are signs of pressure for pistol cartridges? I know signs for rifle but what about reloading pistol cartridges?
most are the same as with rifle. primers flattening some, flow back around the firing pin indent, primer pocket expansion, and case head separation in worst case scenarios
Primer flow is an example of gross over-pressure. There really aren't any sure fire methods of determining the high end of safe pressure because most handguns operate at pressures well within the capabilities of brass casings. Also autoloaders often headspace by hanging on the extractor, so a flattened primer might not be telling you much.
My M&P has the best casehead support I've seen. I could run pressures high enough to loosen SP primers before the case would bulge. So I try to stick to published data.
Yeah, with rifles the only way most of us can get a good idea of pressure is with with a chronograph or something like a Pressure Trace, all the other methods really don't tell you a lot except when you are way over.
I'd trust a $100 Pro Chrono far more than primer shape.
Or just stick with tested data.
most are the same as with rifle. primers flattening some, flow back around the firing pin indent, primer pocket expansion, and case head separation in worst case scenarios
Flow back can be caused by an oversized firing pin hole