Kyle Holsclaw Jr. learned to shoot an AR-15 assault rifle competitively at the age of 16 while attending a clinic run by the U.S. Army.

“It was a fantastic experience,” said Holsclaw, an experienced competitive target shooter who said he had never learned to compete with the AR-15 before the seminar he attended in 2014. “I learned a tremendous amount about how to move with the gun.”

Holsclaw is among the children, aged 9 to 18, who come to an annual clinic run by the elite U.S. Army Marksmanship Unit at Fort Benning, Georgia. The workshop—which will be held this year from October 21 to 23—focuses on practical shooting, a sport that simulates combat shooting conditions. The Army workshops highlight the growing popularity of assault rifles among civilians. Once reserved for soldiers, assault rifles like those used in the marksmanship clinic have been purchased by millions of private citizens.

As assault rifles have moved from armories to family homes, a subculture of sporting competitions that use these weapons has emerged. The Army clinics train children to compete in the hundreds of contests held around the country where participants wield assault rifles. But critics of practical shooting say the sport encourages violence and should not be taught to children—especially at a time when recent mass shootings have reignited debate over gun violence.

Holsclaw estimates that he fired 400 rounds a day during the practical-shooting clinic. Some clinics taught by the marksmanship unit involve Olympic-style target shooting, for which shooters stand in one place while aiming at round, paper targets. A separate clinic focuses on practical shooting, also called action shooting, in which participants move while firing at human-shaped targets using assault-style rifles such as the AR-15, shotguns, and high-capacity pistols. The Army Marksmanship Unit’s annual shooting clinic for children at Fort Benning is the only one of its kind conducted by the military. About 350 children have participated in the Army clinic since its inception in 2008. Other clinics that teach practical shooting to children are run by private organizations around the country.

Practical-shooting participants “take on obstacle laden shooting courses”—called stages—“requiring anywhere from six to 30 plus shots to complete,” according to a description on the Army Marksmanship Unit’s website. “The scoring system measures points scored per second, then weights the score to compensate for the number of shots fired. If the shooter misses a target, or shoots inaccurately, points are deducted, lowering that all-important points-per-second score.”

Speed and accuracy are essential to the sport. “A fast run with poor hits or misses is likely to cost you the match just as perfect shots and a slow time will not win,” according to the website. “The key to success is a balance of speed and accuracy, just like a gun fight.”

In practical-shooting competitions, participants move between firing ranges that look like real-life combat scenarios. One of the “stages” at Fort Benning is designed to look like a rooftop.

“The most important is to learn to shoot effectively while moving quickly,” said Katie Harris, a member of the marksmanship unit who ran the practical-shooting clinic for children in previous years. “When kids get on the rooftop they have to jump up there as fast as they can so they can engage all their targets.”

During the three-day-long Army workshop, participants spend their days on the marksmanship unit’s eight shooting ranges spread across 240 acres at Fort Benning. A typical day starts at 8:30 a.m. with a flag-raising ceremony. The children then head to the ranges in small groups, where they are taught the fine points of gun handling and maintenance, along with movement between stages.

At night, clinic participants and their parents socialize with cookouts. Holsclaw recalled how the instructors inspired him with their upbeat attitudes and technical shooting skilled. While the instructors were strict when it came to safety, they “were absolutely hilarious and kidded around with us,” he said.

Spots in the practical-shooting clinic are in high demand. In previous years, the 50 spots were quickly filled and some applicants were placed on a waiting list. This year, the clinic was limited to 15 participants to provide more personalized instruction. To be accepted, applicants must already have participated in practical-shooting competitions.

“These are high-level clinics, so we don’t want to be just training kids how to draw from a holster,” said Sergeant Michael Buss, one of the organizers. “We are teaching them the fine details that will help them win competitions.”

Even though the children at the clinic are required to be experienced shooters, safety is a priority. On the first day of the clinic, participants are briefed on safety procedures and told when they can and can’t touch their guns, said Harris. “A couple of kids have pulled weapons out of their holsters when they shouldn’t and parents freak out,” she added.

Harris herself began shooting at the age of 13 after her father, who owns a gun range, introduced her to the sport. Now a competitor in practical shooting, she joined the Army in 2014 and was attached to the marksmanship unit.

“I was drawn to practical shooting because it’s such an exciting sport,” Harris said. “It’s a thrilling challenge to walk up to a stage while changing magazines and remembering how many targets you are shooting.”

The clinic is intended to publicize Army careers. “We want to let the kids know that there are opportunities in the military,” Harris said. Many of the children who participate in the clinics hope to one day join the Army Marksmanship Unit, whose members have won six Olympic gold medals. Some of the current members of the unit participated in the clinics when they were children.

Practical shooting’s main governing body in America, the United States Practical Shooting Association, claims its 25,000-person membership is growing. There is no charge for the Army clinic but the association offers scholarships to children who need financial assistance for travel and hotel expenses to participate.

Practical shooting, along with a similar sport called defensive pistol shooting that is also taught at the Army clinics, is practiced at competitions around the country. The International Defensive Pistol Association defines the sport as “the use of practical equipment … to solve simulated ‘real world’ self-defense scenarios.”

The activity has been criticized for promoting violence. “Combat-shooting competitions are built around fantasy scenarios, with humanoid ‘bad guy’ targets to be shot and similar ‘hostage’ targets to be avoided,” according to a report by the Violence Policy Center, a gun-control-advocacy group. The elaborate ‘courses of fire’ feature names such as ‘Carjacked by Gang Members,’ ‘Helicopter Raid,’ and ‘Save the Bank.’ Combat shooters typically begin them with a rapid draw from a holster, and are then timed as they run, crawl, and sometimes climb through the course, all while firing at human-scaled targets.”

Josh Sugarmann, the executive director of the Violence Policy Center, said his group is opposed to children participating in practical shooting because “experts say that children do not have the emotional maturity to know how and when to properly use firearms.”

The instructors said practical shooting is only a sport, but there is a practical side to the training. Some of the techniques that members of the marksmanship unit develop for use in competitions are also taught to soldiers who may be firing their weapons against real enemies, said Buss. Competitors learn to control their heart rate and breathing while shooting under stress, techniques that “also apply to combat,” Buss said. Between 2009 and 12, the unit’s members were deployed to Afghanistan to train soldiers there. They also help develop weapons that eventually make it onto the battlefield.

Harris said the sport of competitive shooting shaped her views about the right to own firearms. “The whole world thinks that the guns are so bad,” Harris said. “But seeing people peacefully shooting at competitions proves that it’s the people who make the bad decisions, not the guns.”

Instructors at the Army clinics do not discuss gun laws with students, Harris said, but “we do emphasize the fact that there is nothing wrong with having a gun in your hand as long as it’s pointing downrange.”

Holsclaw said the skills he learned at the Army’s practical-shooting clinic are useful for self-defense. For example, he said, he learned to shoot attackers from around a wall. “The instructors teach you how not to get shot if you are being shot at,” Holsclaw said. “You are being trained to control your environment by finding the best possible position for your shooting. You learn how to shoot in a way so that you can defend yourself and your family at the same time.”

The assault rifle Holsclaw learned to use at the Army clinic is similar to the millions of others owned by private American citizens. As the number of civilians who own assault rifles grows, gun owners are seeking ways to use their weapons for sport or self-defense and passing their skills onto their children. Marksmanship clinics are one way of teaching a new generation of Americans how to use their firearms—courtesy of the United States military.