Strange, I myself witnessed a similar miracle last Saturday. I have a OLD Jennings J22 I took in as part of a trade a few years ago. This thing would not fire more than 3 or 4 rounds without some kind of malfunction. With mini mags it would run better but not great. Last week I picked up a 500 rnd box of Remington Thunderbolts. Started with a clean gun and now I’m at 250 rounds and not a single malfunction! It’s so dirty the slide is starting to drag but still running. Going to see just how long it will go.