I personally know troops who have shot insurgents several times with M4s at lethal ranges (less than 200') and they took the hits and kept fighting long enough to return fire. Those same insurgents hit with a 7.62 slug would be DRT. Full stop. There is a reason quite a few Marines and soldiers carried .357 revolvers in Vietnam. The reason was the stopping power. The 125 grain .357 traveling at 1400 FPS boasts 96% one shot stops on human torsos that are not armoured. The .357 is still the gold standard for handgun stopping power. Like you with your 1911, I'm a .357 guy. If I cannot do it with six, I need something belt fed. Plus, like a lot of guys I know, I favour a New York reload anyway.
Stay safe.