When we were shooting pins, one thing I noticed is nothing would go completely through the pin unless hit very close to the side. The round that went the deepest was 9mm luger. I shot .44 mag (full house loads) and they only went halfway, if that, into the pin before they transferred all their energy and set the pin flying. Cast bullets work the best.
I did dissect some of the pins and found some of the commercial hard cast to be almost undamaged. Below is what some of the 44's I shot looked like when removed from the pin. These were swaged with dead soft lead