"It's going to be tough," the 34-year-old security officer, whose nickname is Goldfinger, told Reuters. "Doing well at the Commonwealth Games is different and it was some time back.
"With China and Japan in, it will be a different level of competition," said Jung. "I can't predict I would win any medal but I'll be happy if I perform well."
Jung is one of India's biggest medal hopes in the Doha Games, which open on Friday, as the nation's rapidly improving shooting squad aim to augment their meagre tally of just two gold medals from previous Games.
India won only two silver medals in Pusan, Korea, in 2002 and are braced for a world-class competition this time, led by China, South Korea, erstwhile Soviet republics Kazakhstan and Uzbekistan and the Gulf nations.
In the weaker Commonwealth field in Melbourne, Indian shooters won 16 of the nation's 22 gold medals.
Despite the problem, he was named the best athlete of the 2006 Games.
In Qatar, he will compete in four individual pistol events -- free, standard, air and centrefire.
Rajyavardhan Rathore, a Melbourne champion and Olympic double trap silver medallist, men's trap world champion Manavjit Sandhu and air rifle shooter Gagan Narang are also in the fray.
Shooting officials were heartened by India's display in the world championships in Zagreb in July when, for the first time, they won two gold medals.
However, one of the winners, air rifle shooter Abhinav Bindra, has since been sidelined to undergo treatment on a back problem.
(Additional reporting by Sujith Nair)