The M14 can't legally be sold to the public because it has a selective fire receiver. Now, a 7.62mm rifle is useless in full-auto fire, but that's the law -- no auto weapons for the general public since 1986.
3rd World countries don't want M14s. They're poor, not foolish. The FAL is a better weapon in the M14 class, as is the G3, and armies today want a more compact weapon anyway, which sends them to M16s if they are close to the USA and AKs if they aren't (AKs are dirt cheap. 40 million built, and Chinese slave labour is working three shifts making more. Supply has crushed demand...).
A friend of mine carried an M14 in Afghanistan. Specifically, because of its range. In his hands, it was very effective from one side of the valley to another, where the M4 was basically out of accuracy beyond 500 yards. I liked the M4A1. (I think the rails system needs work, though). One of the few pictures I have of me from there, I'm holding his M14, which is kind of funny because I think it's the only time I picked it up!
The 77 grain bullet mentioned was developed by Black Hills for the ill fated (ill-conceived) SPR. From the M4 it is more effective than the horrible M855 greentip round, which overpenetrates humans and other animals. The Marines wanted to penetrate a steel helmet at 800 yards, which is why that round is the way it is.
Many of the problems with reliability are due to crappy, lowest-bidder, minority-set-aside-contractor magazines. Most of us have hoarded old mags.
When I first learnt to clear buildings, it was done with pistols. Nowadays it is done with rifles... much more effectively. While the M4 is very short, the M16 is only 39 inches (1 metre) long. I can't imagine anyone downing an M16 to clear buildings with an AK-47... the 16 points a lot more naturally. And yeah, I've fired a lot of rounds through both of them.
I suspect the guys carrying AKs were just trying to look, what's the Marine term, "salty?" In the Army we'd say, "Hollywood!"
A 9mm pistol will disable a motivated man with any hit that a .45 will. And will fail to disable him with any other hit. Bullet placement is the alpha and the omega (hopefully, the omega for the other guy). I like the idea that somebody had, about making handguns a private purchase item (some police departments do this already). Unfortunately, the Army is overrun with Clintonistas. They are especially prevalent in the MP Branch and Army policy enforces a gun ban regime that would do Adolf himself proud.
I do think that John Browning was an almost supernatural designer. His M2HB still rocks. The .45 is a very fine weapon (that's what I was clearing buildings with, Back In The Day) but the M9 is also an excellent weapon. With decent mags it's 100% dependable. Unfortunately, it had to follow Browning's .45. Like, who remembers who was the second guy on the Moon, the pope who came after Saint Peter, or the first Vice-President of the United States?
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