Not to argue tom, but the United States Military caused the distrust of the M16 themselves. In an effort to save money, they used the same ball powder to load the 5.56 round as they had been using to load the 7.62 (308), and the two rounds NEEDED DIFFERENT BURN RATE POWDERS. The error in being CHEAP WITH SOLDIERS LIVES, caused the M16 with it's tighter tolerances to FOUL QUICKLEY, and thereby FAIL TO FEED. As soon as this powder error was corrected, the M16 became reliable. Was it perfect? Of course not, but neither was the M14 with it's open and exposed Garand action.
I have been fortunate in my past career to have been able to fire thousands of 223 in the AR15 platform, and can honestly say, I have never had a failure with a properly maintained AR. My youngest son has more actually combat experience with the M4 than anyone I "PERSONALLY" know, and because he was a Patrol Leader Sgt. his was a select fire. The 82nd Air Born was in the thick of it, in Afghanistan, and Iraq, and he stated that none of his squad experience weapon failures in the countless firefights they were in in that 3 years.
In reality, the human being is one of the most THIN SKINNED animals on planet earth, and a large caliber is not really needed to get to the boiler room. Your remark of a "good shot", verses a "bad shot", is DEAD ON.