DO YOU LIVE IN AN AREA WITH HARD WATER
Sorry, cheap joke!
That is crazy, if the bullet blew to bits would be one thing, but you have almost a perfect bullet.
What did they weigh?
60+% weight retention is about what you should expect.
Energy is energy, and any bullet that weighs the same and expands to the same dimensions and retains the same weight should penetrate almost the same.
The manufacturer is irrelevant!