Well M16s aren't very lethal they are designed to wound the enemy since that forces them to rescue more wounded troops.
The AK47 carries a more lethal round so terrorists picking the M16 over the AK47 are idiots.
But the problem is the terrorists have taken over ground the US once controlled but Obama has allowed terrorists to retake it while he fucks over Americans here with obamacare, the IRS, higher gas prices, no jobs, etc.
Plenty of people killed by M16s and the gun is far more accurate than the AK. The US regularly beats assholes carrying AKs.
But the point is that the M16 is hardly the weapon of choice in that part of the world. It requires a tail of ammunition, magazines and spare parts. So this guy didnt just happen to pick one up soemwhere. It was an issue weapon with accompanying supplies.
He probably captured from the fleeing Iraqi army...They have U.S, tanks and Humvee s as well...Although they could have gotten them from Obama with help from that nut John McCain