Gray has relived her nightmare final shot that cost her a medal at the Beijing Games everyday since, but the US shooter can rest easy now after sweeping to the 2012 title.
The 28-year-old from Lebanon, Pennsylvania, was so dominant at the Royal Artillery Barracks that she could have afforded a career worst with her final shot as she totalled an Olympic record 691.9 to take gold.
Serbia's Ivana Maksimovic finished in second with 687.5. Adela Sykorova of Czech Republic was third with 683.0.
"It was almost a bit of relief," Gray said about her feelings after her final shot.
"I have dreaded that last shot for four years and it is amazing to have it come true and be a good shot and I took a good shot that was the big thing."
In Beijing, Gray was in the medals before a woeful 8.7 final shot saw her tumble down to fifth as her rivals moved up to the podium by shooting far closer to the 10.9 maximum.
The disappointment was tough to get over but the technical coach for the Columbus State University Rifle Team was wise enough to learn from her mistakes.
"I worked on taking that last shot for four years. Every final I have been in I have thought about being in the Olympic final having to shoot a good last shot and it paid off.
"Without that last shot (in Beijing) maybe I would not have paid so much attention to really trying to work on that last shot."
The hard work paid off and, with the luxury of a 2.7 point lead entering the last round, her near perfect 10.8 to finish brought huge cheer from a capacity crowd at the Barracks with LOCOG chief Seb Coe amongst those applauding.
Gray had entered the 10-shot final from a standing position with a two-point lead after the 60 shot qualifying, where shooters fire 20 shots from each of the three different positions of prone, standing and kneeling.
The American extended her lead with an opening 10.5 and was rarely troubled as she eased to a comfortable victory, with Maksimovic never able to get closer than 2.1 points behind.
Gray could even afford a disappointing 8.9 in the penultimate round, which brought groans from the crowd.
"I just threw it out and did a great job of just going 'OK, it is over, it doesn't matter' and move on to the next one," Gray said of the wobble.
"I didn't need that high score (with the last shot), but after shooting an 8.9 on the ninth shot you know you want to come back from that and that's what I did. It is awesome."
It was the U.S. team's third gold of the Games in shooting following their successes in the men's and women's skeet via Vincent Hancock and Kim Rhode, the most they have won in the sport since 1984.
Serbian Maksimovic said her arms and legs were shaking throughout the final and the 22-year-old threw in some nervous scores of 9.1 and 9.3 twice but her hard work in qualifying gave her the cushion to claim silver.
That medal, which brought floods of tears, will sit alongside the gold won by her father and coach Goran in the 10m air rifle at the 1988 Seoul Games.
"Everything I am and everything I did I owe to him and my mother, who is also my coach, and my brother, and everyone who supported me. I am really happy that they were here to see me win silver. It's all because of them."