In 20 years of L.E. I can assure you the shoot to kill and actually HIT ratio isn't very good either. Why? Stress of the situation, individual personality, and lack of training. I was a weapons trainer for 19 of those years including SWAT. These facts are not new. The only uniqueness of Afghanistan, and Iraq are geographical location. Shooting is still shooting, and killing is still killing.
I have carried the AR15, and M16 configured rifles for 20 years in river bottoms in wet, sandy, conditions and also below zero winter, and have never had a failure. I believe there is a reason for that. Anytime I wasn't busy, I was maintaining my weapon.
I also doubt very many have seen more combat conditions than my youngest son. He was a Sgt in the 82nd Airborne, with a combat tour in Afghanistan, and two combat tours in Iraq. He was in the field most of the time. Because of my job, he grew up around the AR15 & M16. I taught him what I had learned. MAINTAIN YOUR WEAPON. I reminded him of this when he left on his first tour, and he drilled it into his squad. In sustained fire fights he personally never had a failure, and he stated that he saw few if any failures in his squad, but others on other teams did experience failures, and it was usually due to DENIED failure to maintain.
The AR15-M16 is a machine, and like any other machine it must be maintained. ANY RIFLE will quit if it is ignored.
One only has to read these forums to see where most of the FAILURES are in long arms. There are far more "whats wrong" questions on other rifles than the AR type platforms. I'm not saying there aren't any, I'm saying know your weapon, and maintain it, and life is good. I have been practicing that for about 50 years with much success.
And I for one would not be here today, had I been carrying a single shot rifle. Many a frontiersman disappeared into historical oblivion because of having a one shot at a time rifle. My ancestors (Cherokee) kept their bows and arrows and carried a single shot rifle, because it was a SINGLE SHOT rifle. When the repeaters made the scene, some of the most practical people to ever inhabit the planet abandoned the bow and arrow and picked up the repeater. As technology changes, we must change.
I would not want to go up against two or there thugs armed with dirt cheap AK47s with a my Winchester, and that Springfield Trapdoor I mentioned. Tactics will only get you so far, and I made my living USING and TEACHING tactics.JMTCW