Since the AP does not have enough to bitch about these days regarding Iraq, they and other news outlets have turned their eyes to they age old debate: Is the 5.56 mm round man enough for the modern battlefield. This is an interesting debate and one that has raged among gun enthusiasts for many, many years.
This all goes back to the 1950s when a bunch of ballistics geniuses decided that "the 7.62 mm round was too powerful for modern service rifles, causing excessive recoil, and that the weight of the ammunition did not allow for enough "firepower" in modern combat." ( Wikipedia). "Firepower" was synonymous with carry-capacity and rate of fire. Simply, a Soldier could should more 5.56 at a higher rate and carry twice as much as opposed to the 7.62.
Giving the 5.56 the lethality edge (at the time) was the round's tendency to yaw and fragment in soft tissue at speeds more than 2,700 ft/s (820 m/s). In layman speak, than means the round is small and fast enough to turn and break apart inside the body.
I can personally testify when this round tumbles, nasty things happen. Up til now the 5.56 had be proudly killing commies and other enemies of the state for over 40 years. What changed? My thesis: shorter barrels and the Internet compromised a round that was a compromise from its inception.
Muzzle velocity (speed) directly correlates to barrel length. The M16 with its 20 inch barrel sported 3,110 ft/s, more than enough to induce the dreaded fragmentation effect. The M4 by comparison with it's 14.5 inch barrel drops the velocity to 2900 ft/s. I am not a firearms expert, but given the high number of reported pass-throughs (where the round goes through the enemy with little or no effect), I contend the decrease make a difference. Not a huge one, mind you, but under the right circumstances to make a difference.
Next point, the Internet. Folks bitched about the 5.56 as long as it's been around. Ask any WWII or Korea vet that hung around for Vietnam what they thought of the 30-06 and 7.62 compared to the 5.56. Well, the Internet gave them a voice. AR-15.com is one of the largest web forums out there. They are vocal and well-read. Their membership includes some of the sharpest ballistics experts in the country. Arguments on bullet size used to be restricted to the club houses of your local shooting range. These experts combined with every-Soldier-a-blogger in combat are making what used to be a rather exclusive private debate among friends into a political issue during an election year.
Enough on the politics, but you get the point. Experts say better aim is the answer, but practical experience dictates that a person inaccurately winged with a 7.62 is more likely to go down that one nicked with a 5.56. Conversely, you better shoot straight with your 7.62 because you can't carry half as much 5.56. Again, it goes back to accuracy.
Other newer rounds are making a case for themselves. Already, Special Operators because of their access to the flexible supply regulations required to get the best Soldiers the best equipment are going downrange with M4 variations based on the 6.8 mm Remington SPC.
From Wikipedia, the 6.8 mm Remington SPC (or 6.8x43mm) is a new rifle cartridge that was developed with collaboration from individual members of US SOCOM. It is midway between the 5.56 and 7.62 in size and velocity with more energy than both. It is particularly adaptable to current 5.56 mm NATO, the cartridge length being relatively equal to the 5.56, the only modification required to the M4 is the upper receiver and barrel. The 6.8 delivers 44% greater energy than the 5.56 mm NATO at 100-200 meters, exactly the type of engagements detracting from the current bullet. The 6.8 does fall short of the 7.62, but maintains the higher carry capacity of the 5.56. (see offset picture, 6.8 on left, 5.56 on right)
The fact that we're having this discussion in public is great. Any discussion that puts better equipment in the hands of Soldiers is fine by me. Personally (if you couldn't already tell), I'm a big fan of the 6.8. Oh, I would also like to see it from a piston-driven AR variant like the FN SCAR, but that is a discussion for another day.