When the United State's Goverment put in their request for a 'new' rifle, "This is about the size of round we want and this is what we want it to be able to do" the only two serious contenders were Colt and Ruger. (Sturm and Ruger) Ruger's version, the 'Mini-14' was the best by far, completely outstripping the M-16 in all fields (accuracy, ease of handling, reliability, and dependability) However, there was just one problem. All of Ruger's '14's' were machined out, and the Colt-16's were 'stamped out'. The U.S. Federal Government went with the Colt because it was cheaper, even though they were well aware of all the test's results, and knew damned good and well that the Colt had lot's of 'bugs' that needed to be worked out.
The Colt's flash suppressor was three open prongs that tended to catch on vines..The Colt had a maximum rate of fire of 750 to 800 rounds per minute...I still remember back in Vietnam when the Lt. came through the hooch passing out new spring and buffer units to replace the older ones. The new buffer units slowed the rate of fire back down to 700 to 750 rounds per minute, placing it on a par with the M-14. That did not solve the problem. Then they passed out new complete rifles that had a chromed chamber. There was a tiny letter 'c' engraved on the bottom of the barrel, letting one know that he had a M-16 with a chromed barrel. That did not solve the problem...Here was the problem, and it still exists to this day. (It was just worse back then, although it's still plenty bad enough today) The rifle does not like to extract. More properly put, the bolt would cycle ( for example, the M-14 will load, chamber, fire, extract, eject, load, in approx. one/one hundredths of a second) but the extractor would strip the brass from the empty hull and leave it in the chamber. Many a good man died over the years due to a jammed up M-16 rifle. In Vietnam, on Hill 881, over two full companies of Marines died taking that hill. Two out of three of them were found dead with their M-16 jammed and them trying to fix it when they were killed.
We were using Colt ammo. They changed ammo . It did not solve the problem. From Vietnam until I know up into the 1990's, all U.S.Marines were constantly cautioned to keep the lower section (tip end) of the rifle's cleaning rod in their pocket at all times. When you got a jam, perform 'immediate action' (a term they came up with to cover their ass) by pulling the bolt to the rear, and taking the section of cleaning rod from your pocket and throwing it sharply down the barrel from the muzzle end, and hoping that it would dislodge the empty hull from the chamber.... I realize that this is 2007, and I know they 'stiffened the barrel' and I know they added the three round burst selector, but I also know that one drop of water, one tiny bit of leaf, a couple of grains of sand, in the wrong place at the right time, and you're out of business. Talk to any of these old timers, and they will tell you about it. If it didn't happen to them, I'll bet they know someone it did happen to...BOTTOM LINE AND IT'S A FACT.. At least up into the 1990's, when the U.S. Marines jumped off of those helicopters in the middle of the s**t, it was 50/50 as to whether those M-16's would work past the second or third shot. It was also standard policy to carry only 17 or 18 rounds in the magazine. Check around. Ya'll will see..