Their base has been shelled 28 times since Sept. 1, the day after President Barack Obama officially ended Operation Iraqi Freedom. They carefully watch cars that speed too close to their convoy on highways, wary of suicide bombers who might try to penetrate their armored trucks. Even an Iraqi kid carrying a pellet gun is seen as a threat.
With daily shootings and deadly bombings, it's clear there's still a simmering fight in Iraq as the U.S. military prepares to leave after nearly eight years, more than 4,400 U.S. troops killed and at least $750 billion spent.
"Bad guys don't go away. When we leave, they'll find another target," McCord, a 26-year-old platoon commander in the 3rd Armored Cavalry Regiment, said on a recent patrol near Iskandariyah, 30 miles (50 kilometers) south of Baghdad.
Asked if he thinks Iraq is stable, McCord said: "I'd be crazy to say it's safe. Is it better than it was? Yes. But it's probably still going to take some time for the government of Iraq to establish the security they want. There are still bad guys here doing bad things."
All soldiers are combat soldiers, as the saying goes, and the American military's mission in Iraq still allows them use lethal force and go on security patrols to protect themselves and their bases. But for the most part, the days of kicking in doors and raiding insurgents' dens are long gone. Iraq may not be safe, but the widespread retaliatory sectarian killings have ebbed.
Waiting against a ticking clock for the government in Baghdad to ask for troops to stay, the U.S. now is watching to see how much of a fight is left in Iraq - and whether the nation's security forces can battle it alone.
Lt. Gen. Robert Cone, who just ended his tour as the Army's deputy commander in Iraq, said he's confident the estimated 675,000 Iraqi soldiers, police and other security forces can adequately protect the country by the end of the year.
But he said gaps remain - mostly on borders and in the sky to thwart foreign threats.
"You still have an underlying heartbeat right now of violence that is still unacceptable," he said in an interview this month before he left. Six American soldiers who have died in Iraq so far this year, and 18 since the announced end of the U.S. combat mission Sept. 1. "Those guys would argue this is a pretty lethal environment," Cone said.
"What is so dangerous about this environment is that it can appear to be relatively calm, and in a moment it erupts in an incredibly lethal way," he said. "Historically, you could look at Iraq and say there is going to be some level of violence. This is a violent part of the world."
Since Sept. 1, 97 U.S. soldiers have been awarded Purple Hearts for being wounded in action in Iraq, including 25 so far this year, according to U.S. military data.
U.S. officials say the Pentagon is quietly weighing options that could call for thousands of troops to remain in Iraq beyond Dec. 31 if Baghdad asks for them to stay. The deadline is required under a security agreement between the two counties, and so far, Prime Minister Nouri al-Maliki has signaled he will not extend it.
Earlier this month, the Senate Foreign Relations Committee warned that U.S. diplomats and State Department employees and contractors may not be safe in Iraq if U.S. combat troops leave. A newly released nationwide poll, funded in part by the State Department, indicates that 57 percent of Iraqis think their country is moving in the wrong direction and that security remains the single worst problem.
Sheep farmer Ahmed Abdul Hussein Sahir said he is cautiously optimistic about security near his home outside Iskandariyah, where his family has lived for nearly 100 years.
"Hopefully, the situation will stay safe after the American army leaves," said Sahir, 57, wearing a dirty blazer over his dishdasha, a traditional dress worn by Iraqi men. "The situation right now is very good. And if they leave, God bless them, and also us."
A steady string of bombings in a two-week period last month killed more than 200 Iraqis, including at least 51 at a Shiite funeral in Baghdad that triggered a small revolt by mourners who pelted security forces with debris. That scene drew comparisons to much larger anti-government demonstrations in Tunisia and Egypt.
There's no indication that level of unrest will spread to Iraq, although extremist groups associated with the Sunni-dominated al-Qaida and Shiite militias already use any excuse available to undermine stability.
Mideast frustration with politics, poverty and the overall dismal quality of life is "something that is visible here in Iraq too - with the added factor of security," wrote Dr. John Jenkins, the British ambassador to Iraq, in a Feb. 2 blog from Baghdad. Noting the clashes that followed the funeral bombing, Jenkins said he was struck "at how much anger there still is under the surface here in Iraq."
The highway billboard in northwestern Baghdad can't be missed: a big skull and crossbones warning that those caught planting bombs along the road will be shot and killed by Iraqi security forces. U.S. soldiers have seen the sign on hundreds of midnight missions as they sweep the streets for the improvised explosive devices, or IEDs.
Sometimes they get lucky and come up empty. The craters scarring the roads and bridges they drive over speak to the times they have not.
"We've found four IEDs and had about 25 detonate," said Sgt. 1st Class Christopher Smith of York, Pa. "Sometimes they blow up before you find them."