Every 6 seconds while not firing the weapon: Loads 25% of the Magazine Capacity (rounded up) into the Magazine from reserves. Can overfill the Magazine up to double the normal capacity. Works even while stowed.
Every weapon whose perk pool includes Reconstruction, exotics first.
Connect your Bungie account and Shard or Keep flags every weapon in your vault whose roll the community wishlists call a keeper.
Connect Bungie account