- 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.
You can read an excerpt from "The Gun" at Esquire's site:
And here's Mikhail Kalashnikov's 2006 take on the M-16 vs AK in Vietnam and other wars:
So, not only are we way, way, way past Vietnam's M-16, but there isn't even an AR-15 you can point to today as the thing you don't want. The closest you could come to saying that in a sensible way is that you don't like any of the wide variety of options in the AR-15 standard.
In the 1950's men customized their cars by "hot-rodding" the engines, transmissions, etc. They tested them by street racing.
Today the desire of men to fiddle with some sort of handy tech has, to some degree, been assumed by the "AR-15 standard". Like Legos, a buyer can mix and match, fiddle forever w/o actually shooting his rifle. Just as most hot-rodders never actually street-raced their Holley-carbureted Chevys or their Hurst-shifted Buicks in that era, most AR-15 fiddlers today have rarely, if at all, shot their jury-rigged AR-15s. And, except for those who have been in the military, virtually none have formal training and experience in the use of those weapons or even the simulation of their use (not that that is required, but it helps when the chips are down).
So the "AR-15 standard" is Pokemon or Lego for adults. Entertaining, costly, with unending variations, it is a "scissors, rock, paper" for AR-15 buffs. It has an associated symbolic status value among a limited group of people and is largely harmless (even in time of conflict, I would add), unless you're married to one of them and have a limited budget.