Dave,
No nerve touched! I just wondered what assault rifle used in combat was the most powerful in your opinion.
Now I see you're mixing apples and oranges. You're referring to the cartridge! A .50 BMG backs those you mentioned completely off the board.
However, what makes the M-16 more powerful is its rate of fire, accuracy and combat load. Two 30 round clips taped together made for an awesome amount of firepower not counting the taped clips in reserve. The biggest advantage of the M-16 is that it can deliver automatic fire accurately. Neither the M1 nor the M14 could do that! Firing an M-16 on full auto is like holding a garden hose nozzle on something compared to holding the hose 6 feet back from the nozzle with an M-14.
In a duel, an M-16 shooter could get his whole clip on target by the time the others could get their second shot fired. Since he wouldn't really need to aim an M-16 in such a duel because he could just hose his target down, the other guy would never even get an aimed shot off.
If you've never fired an M16 on full auto, you should see if you can arrange it. The newer ones only allow a 3 shot burst, but even then you'll be tickled!
In an infantry company, every man with an M-16 is like a walking WWII machine gun but with a higher rate of fire.
The most powerful combat assault rifle is the most effective one, not the one with the biggest cartridge.
The .223 bullet has a habit of tumbling when it hits something, like flesh. Consequently, all of its energy ended up in the target instead of going clean through. Even hitting an enemy in the upper shoulder put them down. "They" told us it was due to "hydraulic shock" of all that energy being dissipated at once. Whatever....
The M-16 is extremely effective in semi mode because it's a very accurate weapon that can reach what you can see. When a wave of enemy comes at you with AKs rattling, the M-16 is very effective in auto mode because it's still a very accurate weapon for every shot.
Finally, it inspired the Soviets to redesign the AK-47 to fire 5.56mm rounds. Why? They were jealous of the M-16 and its performance in Vietnam. Imitation IS the sincerest form of flattery....