The Waterford native was one of 11 athletes yesterday selected to represent Ireland at the Chinese capital from August 22-28.
World Universities champion Barr is currently ranked 10th in the world, having lowered his national record to 48.65 at a Diamond League meeting in Rome earlier this summer.
Not since Derval O’Rourke and David Gillick in Berlin back in 2009 has an Irish sprinter featured in a world final.
“If I can keep going as I am and get the best out of myself, there’s no saying what will happen in Beijing. The final is where I want to be,” said Barr.
“To get through rounds out in Korea at the World University Games and to win in a particularly fast time bodes well for Beijing.
“Each day is going to be like a final. I’m going to be going hell for leather.”
Reigning 50km race-walking world champion Rob Heffernan, competing in what will be his fifth World Championships, is Ireland’s sole medal hope.
The 37-year-old enjoyed a positive month’s training in Ifrane, Morocco and is in fine shape despite his disqualification over 10km at Sunday’s national championships.
“I feel good. My training has gone well the last month. If I’m in a good place mentally and physically in Beijing, I can give a good performance. I want to win a medal.”
The Togher native will be joined by Brendan Boyce over 50km, while Alex Wright, selected for both the 20km and 50km in what will be his first major championships in the green singlet, is expected to focus on the shorter distance.
Mark English (800m) believes his participation at Moscow two years ago will stand him in good stead. Despite a disappointing showing at the European U23 championships last month, the two-lap specialist hinted at a return to form when clocking a season’s best of 1:45.49 in London on July 25.
“I’m going to go out there and give it a blast. I think I’m back to my old best.”
The Irish team is completed by Tori Pena (Pole Vault), the men’s 4x400m relay team and 3,000m steeplechasers Michelle Finn and Kerry O’Flaherty.
Commented High Performance Director Kevin Ankrom: “I see these championships as the ultimate dress rehearsal for Rio. Overall, I am looking for the team to deliver performances on the world stage which they can build on for the Olympic Games.”
Athletes who failed to achieve their respective qualifying time, but are still in contention for selection through the IAAF quota system include Kelly Proper (200m), Sara Treacy (3,000m steeplechase), Ciara Everard (800m) and Ben Reynolds (110m hurdles). They will learn of their fate tomorrow morning. Ciara Mageean, in the quota over 1500m, has opted against selection in a bid to recover from a recent injury.
Thomas Barr (400m hurdles), Mark English (800m), Kerry O’Flaherty (3,000m steeplechase), Michelle Finn (3,000m steeplechase), Tori Pena (Pole Vault), Alex Wright (20km/50km race walk), Robert Heffernan (50km race walk), Brendan Boyce (50km race walk), 4x400m relay (Thomas Barr, Mark English, Brian Gregan, Brian Murphy, Richard Morrissey and Timmy Crowe).