Vinh is left out of thetop three after scoring 658.5 points - just 0.1 point less than thebronze medal winner, Wang Zhiwei of China.
Jin Jongohfrom the Republic of Korea took the gold with 662 points, followedby countryman Choi Young-rae who scored 661.5.
TheVietnamese marksman is expected to earn a place in the final roundbefore departing for the Games. He exceeded expectations on Aug. 5when he became the fourth-highest point shooter after the qualificationwith a score of 563 points.
At one point, Vinh's score isonly three points less than that of the third-ranked Wang of China –raising hopes for Vietnam's first Olympic medal.
Vinh also performed well in the eighth series, jumping to third place with 78 points.
But when his attention faltered for a second, Vinh scored only 7.3 inthe ninth series and fell out of the top three. Although he correctedhis mistake with 10.2 points in the final series, this is not enough forhim to win a medal.
The score, however, is a significantpersonal achievement: the highest score that Vinh has attained since thestart of his career. It is also an achievement for the country, as Vinhis the first Vietnamese shooter to win a place in the Olympics and hisfourth place here is the highest honor Vietnam has achieved ininternational competitions.
Vinh also took part in the men's 10m air pistol event last week but did not make it to the final round.
After shooting, Vietnam will compete in London in taekwondo, wrestling and track-and-field events.
Two taekwondo martial artists, Le Huynh Chau and Chu Hoang Dieu Linh,and female wrestler Nguyen Thi Lua will start their competitions on Aug.8, while high jumper Nguyen Thi Viet Anh will compete on Aug. 9 andpetite athlete Nguyen Thi Thanh Phuc will walk two days later.-VNA