For a known good product or known good parts that I’ve assembled I trust a gun after 500 rounds.
For an unknown product-parts I’d want to go 1500. I choose that number because 1500ish rounds is when parts from PSA caused malfunctions for me. They used a cheap extractor spring in their BCG. I think it was at about that number that a S&W buffer spring wore out, too. Those are both wear items, but not 1500ish rounds wear items.
IME a lot of problems will manifest within a few hundred rounds. But it’s not uncommon to see things break at the 500-1000 round mark.
If it’s just a gun you wanna shoot at stuff recreationally then I wouldn’t do any of that. I’d just shoot it and enjoy it.
