Military’s gun of choice under fire

Some units looking beyond Colt
Special Operations Command is replacing the M4s and several other rifles in its arsenal with FN Herstal's SCAR, which comes in two models: one shoots the same 5.56 mm round as the M4; the other a larger 7.62 mm bullet and costs several hundred dollars more. Both SCARs can accommodate different-size barrels allowing the weapons to be fired at multiple ranges.

The SCARs are more accurate, more reliable and expected to last far longer than their predecessors, said Navy Lt. Cmdr. Marc Boyd, a command spokesman.

"SOCOM likes to be different," says Keys of Colt, using the acronym for the command. "They wanted something unique."

With the SCAR not yet in full-scale production, Heckler & Koch's HK416 is being used by elite units like Delta Force, the secretive anti-terrorism unit. The command would not comment on the HK416 other than to say there are "a small number" of the carbines in its inventory.

A key difference between the Colt carbine and the competitors is the way the rounds are fed through the rifle at lightning speed.

Mixed messages
The SCAR and HK416 use a gas piston system to cycle the bullets automatically. The M4 uses "gas impingement," a method that pushes hot carbon-fouled gas through critical parts of the gun, according to detractors. Without frequent and careful maintenance, they say, the M4 is prone to jamming and will wear out more quickly than its gas-piston competitors.

"A gas piston system runs a little bit smoother and a lot cleaner," says Dale Bohner, a retired Air Force commando who now works for Heckler & Koch. "If the U.S. military opened up a competition for all manufacturers, I see the 416 being a major player in that."

Outside of Special Operations Command, there seems to be no rush to replace the M4.

Brig. Gen. Mark Brown, head of the Army office that buys M4s and other combat gear, traveled to Iraq and Afghanistan last summer to get feedback from soldiers on Colt's carbine.

"I didn't hear one single negative comment," Brown says. "Now, I know I'm a general, and when I go up and talk to a private, they're going to say everything's OK, everything's fine. I said, 'No, no, son. I flew 14,000 miles out here to see you on the border of Afghanistan. The reason I did that was to find out what's happening.'"

Sen. Jeff Sessions, R-Ala., says the troops may not be aware of the alternatives. He wants the Pentagon to study the options and make a decision before Congress does.

"Sen. Coburn has raised a good question: 'Do we have the best personal weapon?' And I don't know that we do," Sessions said. "We're not comfortable now. Let's give this a rigorous examination."

More from msnbc.com   Sluggish new home sales show rocky recovery   Now boarding: Flight 1225 to North Pole Racist webcam? TheGrio's test says no Kim Peek, a man who inspired more than ‘Rain Man’ Answer Desk: Gold may be riskier than it seems

MORE FROM MILITARY

Military Section Front

War vets, shelter dogs heal together in program General: No trials of pregnant soldiers in Iraq Vets still waiting for GI Bill payments Military families find support away from home Anti-whistleblower culture persists in D.C. Going outside the military box in Afghan war Military Section Front   Add Military headlines to your news reader: