Everybody knows the military makes the best shit, but I couldn't take my Special Forces gear to New York – it would just look strange," says Jason McCarthy, ex-Green Beret and founder of the GoRuck bag company. "I wanted to build a military-grade rucksack that would be as comfortable in Brooklyn as it is in Baghdad."

McCarthy, 34, entered business school in 2009 with plans to start a security-consulting firm that would offer instruction in packing a "go bag" – a pack full of supplies that could carry people through any emergency. But he quickly realized most bags on the civilian market weren't tough enough. So he started designing his own. "I used and abused some of the best bags available during my time as a Green Beret," McCarthy says. "I knew what worked."

McCarthy spent two years developing the bags that make up most of GoRuck's product line (four styles, starting at $195). Early on, he battle-tested his prototypes, literally – sending them to Green Beret buddies in Afghanistan and Iraq. Then he grew concerned about sending unproven gear to men in danger, so he established another proving ground: the GoRuck Challenge. In these team-oriented endurance runs, which are led by combat veterans and incorporate Special Forces training, participants carry a GoRuck sack loaded with rocks or bricks.

The results: super-rugged bags (all handmade in the U.S.) with a minimalist look and maximized features. Every GoRuck sack is made from weatherproof Cordura (a tear-resistant nylon) and loaded with military-inspired extras like silent zipper pulls and cross-stitched stress points that can withstand 400-plus pounds of pressure. Slim enough to squeeze through small doorways in Afghanistan, the packs open to a surprising amount of surface area – when they're unfolded like an Army medic's trauma pack, everything inside is quickly accessible. "We just took the essence of what makes Special Forces gear great and translated it for the civilian market," McCarthy says.

Jim Markel Jr., 46-year-old CEO of Red Oxx Manufacturing, had the same instinct. A former paratrooper and parachute rigger with an elite Marine unit, Markel was in charge of packing and maintaining the chutes troopers depend on. "We have a saying baked into us in rigging school," Markel says. "It goes: 'I will be sure. Always.' "

Markel spent four years in the military before leaving in 1989. He then teamed up with his father, Jim Sr., who'd retired to Montana and was making weightlifting straps and harnesses under the company name Red Oxx. In his off time, Markel went hunting, fishing, and river-guiding. But he quickly tired of flimsy gear. One day, after the handle ripped off a new rifle case – "I hadn't used the darn thing once!" Markel says – he decided to make his own. When a buddy noticed how well crafted the case was, he asked Markel to make one for him, too. Around the same time, another friend asked Markel to make him a garment bag. "He knew this was the kind of stuff we'd do on the side in the military to make extra beer money," Markel says.

Soon, he was taking orders from friends-of-friends, sewing in his parents' basement, and burning nylon on their stove. His fed-up mom kicked the operation out of the house, but by then, the new Red Oxx was born.

Today, the company rakes in $2.5 million a year for its line of durable bags – carry-ons, duffels, briefcases, garment bags, and rucksacks, from $20 to $265 – all handmade to Markel's exacting standards in eye-catching colors. Oversize chain zippers are made of Delrin, a plastic that doesn't corrode. Heavy-duty nonslip rubber straps stay flexible to minus-40 degrees. Inner compartments have steel turn locks.

Like McCarthy, Markel personally tests his products in the field, carrying them on safari and through jungles. "I wear this stuff out," Markel says. "I'm not cutting corners. I want to make a product I can be proud of."