Campbell set the Scottish record in the javelin throw in 2006, throwing for a distance of 73.18 metres (240.1 ft) at the World Junior Championships in Beijing, ranking him 8th (junior) in the world.
In 2009 Campbell improved his lifetime best to 76.71 to set his 3rd National record of his career.
At the Commonwealth Games trials, just weeks after he became UK Champion in 2010, Campbell became only the 10th Briton and 3rd British Under 23 to ever throw over 80m recording a new Scottish National Record and a lifetime best of 80.38.[3]