Eric Engler doesn’t have any military or law enforcement training, but he’s considered deadly with an AK-47. Lest anyone underestimate his marksmanship, he once shot five Marines in rapid succession in an abandoned Virginia prison.

Actually, Engler’s “kills” were sanctioned by the U.S. military; he was hired to gun down his fellow Americans. Engler, 42, is the owner of Engler Custom Paintball Guns of Jeffersonville, a small defense contractor that makes and markets paintball guns and supplies. Because the weaponry closely resembles actual military hardware in look and feel, it has become an important training tool for the country’s armed forces.

In the world of multibillion-dollar Pentagon contracts, Engler’s company is small potatoes. His largest contract to date was one awarded several weeks ago for $82,132 to provide the U.S. Army with paintball gun packages. Unfortunately for him, the contract was contested by a competing vendor and will have to be bid again in the coming weeks.

Nevertheless, Engler’s tiny machine shop, which is based in his home garage, is definitely on the U.S. government’s radar.

It all started when Engler organized a paintball game at West Point several years ago. After the “game,” Engler was approached by several cadets who were interested in buying his authentic-looking weaponry. From there, his business took off. A number of federal agencies, including U.S. Customs and Border Protection and the Rascon School of Combat Medicine at Fort Campbell, Ky., have since purchased his paintball equipment — mostly, to simulate real-life combat situations.

In the Virginia prison scenario, for example, Engler and several of his fellow paintball enthusiasts were hired as “bad guys” to help train newly minted Marines to clear a building of insurgents without harming the civilians inside. As Engler recalls, the Marines’ initial performances didn’t make the grade.

“We wiped them out the first day,” he boasts. “It was bad, because these guys were right out of basic training, and this was their first experience working together as a team. So, we’d shoot the first guy and he’d fall down, and the guy behind him would fall down and we’d shoot him, too.”

By the second day, however, the corpsmen started getting the hang of it, as they learned from their earlier mistakes to recognize potentially deadly situations.

That was three years ago. Today, most of those Marines have since deployed to Iraq and Afghanistan. “From what I’m told, their paintball training helped them a lot,” he says. “If we can do anything to save a life, I think it’s a great goal.”

Ironically, Engler Custom Paintball Guns, which relocated to Vermont from Danbury, Conn., two years ago, has yet to make inroads with the Vermont National Guard or local law enforcement agencies. Engler’s not surprised, since most of his company’s sales are conducted online to civilian paintball enthusiasts. As he puts it, “No one in Vermont knows we’re here, except the tax people.”

That, too, may be changing. Last month, Engler organized a paintball game in Colchester for 65 cadets from Norwich University. Although that may sound like a big game, it pales in comparison to other scenarios Engler routinely participates in. One, in Oklahoma, annually reenacts the D-Day landings on the beaches of Normandy and involves 2500 troops per side.

For its part, the military has also begun to recognize the R&R value of paintball games. According to Engler, his equipment is now being used to help returning soldiers blow off pent-up energy and aggression. As he puts it, “Paintball is being used for a lot more things than the Army is willing to admit.”