For re-rolling HoW legendaries, Field Scout is no longer in the perk table. Additionally, Extended Mag is only rollable on the Auto Rifles and Hand Cannons. See this post on Reddit for the full perk table breakdown, as of 5/20/15. http://www.reddit.com/r/DestinyTheGame/comments/36mnjx/how_reforge_guide_possible_perks/ ADDENDUM: Link to perks and their descriptions. Some weapons can have perks similar to Field Scout, but that trade off the increased magazine size for decreased stability (Casket Mag) or decreased reload speed (Appended Magazine). PlanetDestiny.com has the new HoW perks and descriptions listed: http://planetdestiny.com/all-new-expansion-perks/ It looks like Shotguns and Rocket Launchers have no way of permanently boosting the magazine size, but Clown Cartridge and Tripod can still roll on Rockets. Shotguns appear to have been left out of the additional ammo equation.