memtb,
If your bullets shoot through the steel plate, it will make a believer of you! I did take pix of the holes in the plate, but that was years ago and they have probably disappeared.
I’m not doubting the ability of the 45-70 with a bullet of decent hardness to penetrate a 5/8” plate of mild steel or of your tests! My post was a missed attempt at humor.... hence the emoji at the end of the post! memtb