MULLIGAN - Missing a shot has a chance to return ammo directly to the magazine.
5% chance to regain a round into the magazine per shot
In Destiny, MULLIGAN is a Weapon Upgrade that can be found on Uncommon and Legendary Hand Cannons and Sniper Rifles as well as Uncommon Rocket Launchers. Weapons in Destiny pull each Upgrade at random from specific pools (with a few Weapons that are an exception).
To see more info on exactly which Weapons this Upgrade can be found upon click the link below:
To see more about how this Weapon Upgrade fits into these pools, please click the links below:
HAND CANNON WEAPON UPGRADES
SNIPER RIFLE WEAPON UPGRADES
ROCKET LAUNCHER WEAPON UPGRADES