'Hard' Difficulty Challenges = 'Insane' Difficulty for regular Campaign missions

The Hard difficulty for this games Challenge mode is actually the same as the regular Campaigns Insane difficulty and completing those challenges will work towards earning this achievement
It should be noted that i definitely would not suggest going for this achievement solely by completing challenges. While they can be a nice change of pace from the usual campaign with the addition of mutators, a few of them even being helpful (more heavy weapons spawn, all primary weapons having explosive ammo), most of the mutators you're gonna come across are gonna be just flat out annoying (friendly fire being tripled for the whole team, climbing taking away all your stamina and a portion of your health each time). So unless you're looking to make things tougher on yourself or you just wanna make things interesting, avoid these challenges if your sole purpose of playing them is to earn the 'Well, what did you achieve?' achievement.