- The original cartridge (.223 caliber) that the AR-15 was based on was designed for shooting "varmints" (small- to medium-sized furry mammals): In Vietnam it was found that the M-16 tended to wound rather than kill the enemy, and a new doctrine was adopted to suit this fact. In contrast the AK-47 cartridge (7.62x39) was designed to _kill_ large hairless mammals (men) and does so with dispatch.
- In Vietnam the M-16s (AR-15) jammed all the time. To unjam one you had to put a stick down the barrel and dislodge the jammed round, not an easy task when you're lying on your back and VC are shooting at you with ultra-reliable AK-47s. The M-16 is one of the reasons we lost that war. C. J. Chivers writes about the sordid history of the M-16's development and deployment in his book "The Gun" (link below)
I have often joked that the US government _wants_ their citizens to buy AR-15s because an AR-15-equipped citizenry is effectively disarmed.
I was astonished to hear that the Orlando shooter had an "AR-15" since those are usually "Jam-O-Matics". My astonishment vanished when it was revealed that the shooter used a Sig Sauer MCX, which has a better design and does not jam.
https://en.wikipedia.org/wiki/.223_Remington
https://www.amazon.com/Gun-C-J-Chivers/dp/0743271734/ref=sr_...
You can read an excerpt from "The Gun" at Esquire's site:
http://www.esquire.com/news-politics/a25677/ak-47-history-11...
And here's Mikhail Kalashnikov's 2006 take on the M-16 vs AK in Vietnam and other wars:
http://www.haaretz.com/news/ak-47-inventor-u-s-troops-in-ira...
The Author, C.J. Chivers, writes an interesting blog for the NY Times where they attempt to ID munitions from the battlefield in Africa, Syria, etc. http://cjchivers.com/
I read it not so much as a historical text but as a story about dramatic shifts in power attributed to technological advancement and strategy.