Members of the Iraqi security forces pose with weapons. Much of the American-made arsenal ISIS holds was reportedly seized from defeated or fled Iraqi soldiers. Reuters

Islamic State leaders are coveting American-made military gear because the extremist group's typical fighter is using older versions of U.S. weapons, which contradicts the image of its soldiers being equipped with "elite weapons," says a new Foreign Policy report. The report comes despite ISIS' February seizure of a stockpile of American-made armored vehicles and weapons from Iraqi forces north of Baghdad, which is said to be not the first time the group acquired U.S.-made weapons.

Jonah Leff, director of operations for Conflict Armament Research, said American gear makes up a "small fraction" of the 40,000 pieces of ISIS equipment his group has catalogued, and that the coveted U.S. gear tends to go to the top leaders, according to Foreign Policy. Leff said Conflict Armament Research, which tracks illicit arms transfers, has registered about 30 U.S.-made M-16's and 550 rounds of American-made ammunition, according to the report.

Speaking to a small group in Washington, Leff said the average Islamic State fighter is using a Cold-War era AK-47. While the "elite" weapons are handed off to leaders, Leff said seized U.S.-made vehicles have been packed with bombs and are used as suicide vehicles, according to Foreign Policy.

Conflict Armament Research obtains its data through teams on the ground in war zones that document weapons and traces the arms' chain of supply, according to the group's website. The iTrace map on its site tracks weapons back to their origin, and was funded with a $4 million grant from the European Union and Swiss government last September, according to Foreign Policy. The organization might have found that U.S.-made weapons aren't a huge part of the ISIS arsenal, but Syria and Iraq is still full of seized military gear. Much of the gear comes from the fall of the Libyan government in 2011 and from raided Syrian stockades, Foreign Policy reported.

Improvised explosive devices, which took such a toll on U.S. troops in Iraq, might be the most prevalent weapon for the Islamic State. Its bomb makers are building the homemade explosives and placing them “in an industrial scale and in unprecedented fashion,” Leff said, according to Foreign Policy. “We’ve never, ever seen anything like this.”