What he names as the chief problem with the reliability of the M4 results from the fact that the bolt carrier assembly is moving at a much higher velocity than that of the rifle, this due to the higher (doubled) pressure - a product of the gas being tapped earlier. Notice that no where in the "tech note" does he mention that the velocity of the carrier, and thus the motion of the bolt itself (and its extractor) was slowed with the new M4 buffer assembly, identified by the letter "H" (heavy) stamped on its face. The "H" buffer brings the cyclic rate down to approximately that of the standard rifle.
The other problems that he mentions, such as cartridge case relationship to chamber, barrel overheating and resulting molecular changes, etc. are all a direct result of a lack of heat dissipation due to the high rate of fire allowed with the standard (not the "H") buffer. Again, slow down the rate of fire to that of the rifle and you have lowered the reliability problems to approximately the same percentage of those found on the rifle (at least in the areas of malfunction relating to cyclic rate and heat disipation that Mr. Westrom discusses.)
I am surprised that he didn't bring up the possibility of rounds "cooking off" in the chamber after sustained full automatic fire (or continous cycling of the "burst" mode.) This can happen too - on carbine or the rifle. But to do so would not have added his argument against the M4 and for the rifle. I monitored the results of the testing on the M4 closely and remember the problem of high cyclic rate and its ugly symptoms. It was merely a problem of slowing down the machinery so that it didn't destroy itself (and its operator.)
Armalite builds a good weapon - I'm not trying to tear them down as a company. But to me, posting something like this as a "technical note" is something akin to those little advertisements that appear in the newspaper disguised as an actual news article - the ones that the newspaper is kind enough to mark "paid advertisement" in small letters up at the top of the ad for us. There are some facts missing that have a very heavy impact on the story here. And if those facts had been included the story would not have been a story at all. I will tell you that I am disappointed to see what could be called a "high engineering technology" hit piece on the M4 being distributed by Armalite. It was written on such a level so as to leave the average reader with the idea: "I'm not sure what all this means, but it doesn't sound good - hope I don't ever have to rely on an M4."
The M4 has had the hell tested out of it and it works well. As with any new piece of machinery, there are always some flaws that have to work themselves to the surface over time before they can be corrected. That is how the M16 became M16A1 became the M16A2 and so on. I have relied on the M4 while under fire, and will continue to recommend and instruct the operation of it.
Stay armed,
Raven6
Absolutely - it's rapidly becoming the LE/SRT long arm of choice for it's ease of handling, slew of accessory choices, and proven design. For those same reasons, it also makes perfect sense for SOF, aviation, armor and combat support soldiers.
For the infantry rifleman, though, the long gun has specific advantages regarding it's ability to deliver faster transitions, more lethality, and enhanced penetration at extended range. For those reasons alone, I was pleased with the USMC decision.
The A4 offers all the modularity, and then some, of the M4 MWS/SOPMOD and additional velocity, accuracy (arguably) and lethality with a negligible tradeoff in weight and maneuver given the typical infantry mission.
They are giving up some utility in the CQB environment - but they also have the new M1014 combat sgn, it's a bit longer than the M4 but for military CQB ops it offers tremendous firepower and high hit probability.