guyver0313 said:
The M16 was designed because of the problems with the weapons they had in WW2 to my understanding.
Actually, the M16 was designed to replace the venerable M14, which started to phased out during my military time, in the 1960s. The M14 replaced the M1 Garand and provided not only a high capacity box magazine but retained the .30 caliber knock-down power of the .30-06, with a slightly smaller cartridge, the 7.62x51 (almost the same as the .308 Win). The M14 also allowed for optional full auto fire, which was not an option, with the M1 Garand. The M14 was the next logical progression, in the Garand line.
The Italians (specifically Pietro Beretta), after the war, developed the BM59, which was a box magazine-fed Garand, working very similarly to the M14. They are fairly rare.
The average M14 was significantly more accurate, at extreme long range (over 500 yards), than the average M1 Garand. The reason for the fade-in of the M16 was because NATO wanted a uniform round: the 5.56mm, which is, really, only a centerfire .22. As my memory recalls, from that time, the 5.56mm was supposed to be a "less cruel" round, whatever that meant.
There was, also, much talk, at the time, of the 5.56mm spinning/tumbling or causing the enemy to have to utilize two men, for each one wounded, to remove them from the battlefield, etc. Most of that, in my experience, was nonsense. There were infinitely more survivors, who were hit with the 5.56, than there were hit with the solid .30 cal round of the M14 or M1 Garand. The early M16s were considered, by many of us, as Matty Mattel Specials, having no reliable accuracy, beyond 200 yards. They've improved, dramatically, since then but they're still centerfire .22s.
Now, if I had to choose, between the AK47 and the M16, I would opt for the .30 cal round. Not much long range accuracy but extremely effective, as an anti-personnel round. That's only one of the reasons why folks prefer them.
Fortunately, I don't have to make that choice, since I have multiple M1As (civilian version of the M14) and no ARs.
I hope that helps clarify some of the questions.
Gary