If it performs as expected through about 48 hours (6 days) of training classes, that would be a good start. I might tweak some things like grips, holster, cartridge details, sights as I'm getting familiar with it. After another 48 hours in classes, I would consider it well-proven. I would also practice between classes. I won't characterize practice by hours because I don't go at the same pace that is expected from classes.
One would not ordinary expect a revolver to fail, but I have had one revolver fail during practice. That one is completely out of consideration for carry. "Testing" during classes and practice has mostly refined my choices or simply proven them worthy of confidence. For example, in one class, I found the grips I had chosen blistered my fingers. The finger grooves didn't fit. It's not the kind of failure that I would regret having on my carry gun, but I switched grips when I got home. The replacements seemed better in practice, but they were really put to the test at the next class. In another case, I tried a new sight. It did well in one class, but I didn't fully appreciate it until I took it off and went back to factory sight. Again, the factory sight probably wasn't going to get me killed, but having been through a class with it and with another cemented my preference, and it was later confirmed in subsequent practice and another class.
I've used various holsters. Some of them can certainly be expected to perform well, but do not conceal so well. The holster I use for carry conceals well, but I didn't initially have a lot of confidence in it. My confidence has been built up in the course of actually carrying with it, practicing with it, and taking a multi-day class with it where I drew from concealment hundreds of times. I don't have any practical doubts about it anymore. It could have some shortcoming when rolling around on the ground in a fight or something. I do not have a good opportunity to test that kind of thing. Retention is fine, but could I access it? It is a good idea to test your holster, as it is just as important in use and probably more likely to fail than the revolver. How far you go in testing is up to you.
As far as testing ammo, I depend on manufacturers to test things like terminal ballistics. I only test reliable function in my gun, which is quite simple with revolvers that don't need to feed, and I test that I'm getting the velocity that is needed to obtain the results that were intended by the manufacturer. This is primarily a concern when shooting a very short barrel which I've gone away from.
After practice, several days of classes and more practice, I have a pretty good idea of what I can expect from a gun and what might be missing. I recommend at least one revolver-specific class because you will both get instruction specific to the unique demands of revolvers and also see classmates using different revolvers. You will almost certainly see either something that is working better than what you're doing or someone making a mistake in their equipment that you'll learn to avoid.
