Drool inducing.

(Popular Mechanics) — Heads turn eagerly as painfully bright sunlight pours through an opening door of a dark New York City warehouse. Smiles mix with the winces; a celebrity has arrived.

Two men in black T-shirts step into the shadowy building, carrying opposite ends of a large green case; they place it carefully on a table. One unlocks the clasps and cracks open the case, revealing two disassembled Heckler & Koch 416 carbine rifles.

The HK416 is, as of May 2011, the world’s newest celebrity weapon. Enough off-the-record sources have told reporters that it is the gun that killed Osama bin Laden that this detail has become accepted history, even though the Pentagon and HK won’t admit it. It is undoubtedly true that U.S. special forces helped create and use this weapon, making it a logical choice for the Naval Special Warfare Development Group operators who swept bin Laden’s compound in Abbottabad, Pakistan. . . .

German weaponmakers designed the HK416 specifically for, and with input from, U.S. Army special forces. Ten years ago, they wanted a better gun than the M4, which has a reputation for jamming. (There are those who defend the rifle, but U.S. special forces wanted something different.) The M16 and M4 both use gas tubes to launch their projectiles, and keep these gases (along with burned carbon particles) inside the gun, fouling the receiver. The HK416 uses a gas piston instead of a gas tube to launch projectiles. This method allows the weapon to vent hot gas and burned carbon from the rifle with each shot.

This is “the key to the HK416’s reliability,” says HK spokesman Steve Galloway. The reputation for reliability is opening new doors for the company, too. The U.S. Marine Corps is currently in the final stages of testing a version of the HK416 as a candidate to replace some belt-fed light machine guns. Galloway says the company is also eyeing an even bigger prize for the HK416 in the pending Individual Carbine Competition, a contest to find a possible replacement for the U.S. Army’s M4 carbines and M16 rifles.