In the qualification round, Manu shot 575 to end in 17the spot while Heena shot 572 to finish at the 26th position.
The coaches were also a disappointed lot. Given the familiar conditions and that the shooters had entered the stage with genuine optimism, it was an opportunity missed.
The build-up had been ominous with off the field issues threatening to tarnish the upcoming ISSF World Cup without a single pellet being fired.
The 28-year-old Sidhu shot a final score of 38, two of them perfect fives, to claim the top honours ahead of Australian Elena Galiabovitch.
Shooters bank on recent success at ISSF World Cup to turn new leaf after Rio disappointment.