So - you bought someone else's handloads and fired them in your gun? That violates one of the primary rules about ammunition - don't use someone else's handloads.
I frequently see people selling their reloads, or grampa's reloads they found in the attic, and am always amazed when people buy it. IMO it's absolutely foolish to buy stuff like that, but you know that now of course.
All of that has nothing to do with the 5.7 caliber; any reloaded round can be dangerous.
