The Army has a new leap-ahead challenge for gun makers -- build an improved carbine that fires so fast it can put two bullets through the same hole.

Small arms companies are already balking at the "hyper burst" requirement the Army wants as a feature on potential replacements for the M4 carbine. It's not specifically identified in the draft solicitation the service released in late January, but Col. Doug Tamilio, the head of Project Manager Soldier Weapons told me the Army wants a weapon with hyper burst.

Apparently, putting two bullets through the same hole could potentially penetrate some types of foriegn body armor more effectively and incapacitate a foe more quickly.

Officials from Heckler and Koch, Remington Arms Company, LWRC International, Knight's Armament Company and others told me that they know of no company in the U.S. that's has this capability.

Gun makers are describing it with phrases like "That's a significant requirement." and "It's not going to happen." My favorite is from a Remington official who said "It's just silly."

The only company that seems to have it is Izhmach, a Russian arms company that produces the AN94. The AN94 has a burst mode that fires at a rate of 1800 rounds per minute.

The Russians, who are notorious for over-selling their weapons, boast that the AN94 can put a two-round burst through the same bullet hole at 100 meters.

Experts from the small arms community maintain that the AN94, which was fielded to Russian forces in limited numbers in 1994, is not that impressive. Its an extremely complex system that relies on the barrel assembly recoiling reward when the weapon is fired. Those who have fired it say it jams more than it works.

It certainly looks cool on YouTube. Here's video that seems to be in Russian but shows the AN94 firing a lot.

Matthew Cox, a free-lance, defense writer, can be found at http://www.tacticalwriter.com/