The wood-paneled walls of the oldest shooting club in New Jersey are covered with aged, black-and-white photos of men holding rifles and wearing smiles. Trophies from the 1960s line the shelves, and a caricature of an American Indian labeled “Chief Alibi” smiles down on a large American flag. Sketches of hunting dogs, ducks, and hogs superimposed with shooting targets contribute to the rustic, frozen-in-time atmosphere.

Inside, a self-proclaimed “city girl” unpacks her stylish pink suitcase full of shooting gear and begins to assemble her gun.

“It’s my baby,” Sandra Fong, 18, said as she hugged her rifle.

The gun weighs more than 10 pounds and will soon travel to Beijing with the petite Ms. Fong to compete in the small-bore rifle Olympic competition. The youngest of all the Olympic shooters, she is not yet old enough to practice at the shooting range in Chelsea, much closer to the Manhattan apartment where she grew up.

“A lot of the members are generally older, so Tuesday morning, it’s not a hot spot,” Ms. Fong said of the desolate New Jersey club. In a discipline in which most peak in their late 20s and 30s, Ms. Fong is a prodigy of sorts. A young urban woman, she competes in a sport that often attracts older Americans from more rural areas.

The pink suitcase is overflowing with gear. She pulls on a zip-up wool jacket and a purple leather overcoat and pants, and replaces her Converses with square-toe lace-up boots. The heavy gear helps insulate her body’s small, unconscious movements from skewing her aim, but it also causes her to sweat in the unair-conditioned building.

A talkative young woman who just graduated from Hunter College High School, she animatedly tells a story about a time she found a spider in her shoe and “freaked out.” Meanwhile, she removes her shiny red headband and pulls on a bandana printed with flames. The transformation is complete.

She might like pink and be scared of bugs, but Ms. Fong is no girly girl, and she says she thrives under pressure. A focused, dedicated shooter, she beat out many more experienced women, including her older sister, to gain her spot on the Olympic team through sheer determination.

“We kind of have this attitude where off of the range we’re sisters, we’re best friends, but on the range we’re competitors, and it’s not flowers and hugs,” she said.

Ms. Fong has honed her ability to focus while competing, dispensing with sentimentality and other distractions that could make the difference between winning and losing in a sport that requires total concentration.

The small-bore rifle competitors shoot in three positions — prone, kneeling, and standing — for more than two hours, attempting to hit dime-size targets 50 meters away. The most important skills are intense focus and stillness. The slightest movement can send a shot significantly off target, so shooters work to keep their heart rate as slow as possible. Ms. Fong wakes up before 5 a.m. every day to engage in long bouts of cardio exercise and stays away from caffeine and sugar, which can lift heart rates.

“I would say about 60% to 70% of the competition is mental,” Ms. Fong said. “A bad shot, you can either accept it and move on or you can get completely thrown. A lot of it is being physically at your peak as well as mentally on your game.”

Ms. Fong shares her love of shooting with her family. Her father started the craze by taking up his rifle when she was 12, and his three daughters began to join him at the range.

She has struggled with the incongruity of her position: rifle-wielding city girl who has never been hunting and believes in gun control laws.

“The first time I found out that my dad owned a rifle I was like, ‘What?’ I mean, I’m from New York City. Guns are bad. But as long as you know how to use them properly, they’re just tools,” she said.

In competitions growing up, Ms. Fong has made friends with people who raise goats or live in towns with populations of less than 100 people.

“They start talking about raising cows and going mudding and I have to say I’ve never done that. Then they laugh,” she said. “It opens your eyes to other places even within your own nation. With shooting I’ve been able to see that there’s just so many other ways to live and view the world.”

Ms. Fong has also traveled to more exotic destinations with her rifle, even taking her Chemistry SAT II test in Thailand while competing in the World Cup.

Her younger sister, Danielle, who has cerebral palsy, is competing in the Paralympics in September. Ms. Fong won’t be able to attend: She starts at Princeton in the fall.

“Taking a trip with all my sisters to Beijing would have been a dream come true,” she said.

In the Olympic trials last May, Ms. Fong placed second, behind a 24-year-old shooter from Pennsylvania. Her sister Abby, the female national champion, placed fourth.

“Abby definitely puts up a huge fight all the time, and I compete against her most, so it’s often back-and-forth who’s winning,” she said.

They will be on the same rifle team at Princeton.

Though this is Ms. Fong’s first Olympics, and she is nervous, she is going for gold.

“My biggest hope is … to perform to the best of my abilities,” Ms. Fong said. “I know if I can do that, I have a shot at the medals, hopefully the gold medal.”

In the meantime, Ms. Fong says she just doesn’t want to fall down in front of any cameras.