Get the Quest Step while playing the campaign.
Defeat Uldren and reclaim the Ace of Spades.
Take Ace of Spades to Gunsmith.
Get 5 Invader Kills in Gambit with hand cannon (kill the person invading your area times).
Eliminated 250 enemies in strikes with hand cannon.
Get 25 precision hand cannon kills in the crucible.
Open the caches in the solar system.
Complete the mission: 'ACE In The Hole' on Titan.
Visit Banshee in the Tower, collect your ACE of Spades.