Sing's marksmanship at Gallipoli saw him dubbed 'The Assassin' or 'The Murderer' by his comrades. He reportedly acquired the latter nickname due to his callous attitude towards the enemy. By early September 1915, he had taken 119 kills, according to Brigadier-General Granville Ryrie, commanding officer of the 2nd Australian Light Horse Brigade. Regimental records list Sing as having taken 150 confirmed kills, but on 23 October 1915, General William Birdwood, commander of ANZAC forces, issued an order complimenting him on his 201 unconfirmed kills. Historian Bob Courtney noted that an official kill was recorded only if the spotter saw the target fall. If the first shot missed the target, it was very risky to take a second shot, as this could give away the sniper team's position.