A competent commander, Meldrum's WMR played an important role in the Battle of Chunuk Bair, when it captured Destroyer Hill and Table Top features, on the approaches to Chunuk Bair, in the evening of 6 August 1915. It then reinforced the defenders of Chunuk Bair in the evening of 8 August. Later that day Meldrum had to take overall command of the defending forces when the senior officer present was wounded. The WMR was relieved the next day, with 100 out of 183 men killed or wounded. Towards the end of the campaign, he was called up to take over command of the New Zealand Mounted Rifles Brigade. He was later recognised for his leadership during the battle with an appointment as a Companion of the Order of St Michael and St George and by the end of the campaign in Gallipoli had twice been mentioned in despatches.