The 45 ACP was a good round 100 years ago, even 30 years ago. Things change, we evolve. People 100 years ago were a lot smaller than they are today. Big Macs have taken their toll. People today are bigger, stronger and healthier than 100 years ago. The average life expectancy was 47 in 1911 to day it is 77. The average chest wall is twice as thick today as in 1911.
Sure a 45 will kill you stone dead cold, but there are better options today.
My rifle and pistol are tools, I am the weapon.