Of note, back in the day, I had some 3/8" plate steel that I tested a lot of 5.56 on.
M193 would launch spalling and "make it through" (launch a plug out the back) out to about 100m
M855 would penetrate, and then through a 2x6 behind the plate. It would do this out to 150m, where I stopped testing.
Hornady TAP 5.56 T2 would perform similar to M193.
This was all from a 20" rifle.
Velocity is what burns through hard stuff, as is construction of projectile. The .45 ACP is a very slow creature, and it does not do well with hard stuff due to low velocity, low kinetic energy vs. frontal area, and soft projectile construction (typically). using some sort of hard caste bullet with a sharp shoulder may change the dynamic.