I just think when you experiment with those pressures, you should be measuring things.
Actually, it is not that expensive, and much less costly than medical bills...
The latest has a Bluetooth interface available to the PC. The entire package is about $900 shipped.
https://www.shootingsoftware.com/index.htm
When I teach reloading, I make the point that the reloading manuals are not recipe books giving you guidance on working up a load. They are documentation of the results of experiments using specific components and conditions.
They document the safe range of a specific powder, bullet, case, barrel and primer which will predictably operate within SAAMI specifications.
Anything else is an experiment. I don't know about you, but I don't like to experiment with pressures ranging from 40,000 to 75,000 PSI without the proper instrumentation.
While black powder in a revolver is not likely to detonate, I'm not exactly sure what the recoil forces and abrupt slamming of a cartridge into the chamber would do to a chemical that could potentially detonate.
This is one reason that the world had to wait for Smokeless Powder (a fast burning chemical propellant) instead of Black Powder (an explosive that can detonate from physical pressure) for the development of semi-automatic firearms.
I guess that you can take this as my opinion that substituting black powder for smokeless powder in a modern semi-automatic handgun is not a very good idea. While some have done it without injury, I would never attempt to do it.
I'm also not comfortable with using other people's reloads...
Marc