They nerfed loot in this game so bad. I remember in 2017 or 2018 you could get like 7 m 16 from bunker bravo before they even added the underground part.
the most easiest nightmare mode is purification ritual, the 2nd easiest is fertility, the 3rd easiest is the unity ritual, the hardest is the raider, so i recommend doing the nightmare mode only when its purification ritual ( in my opinion bc i only wasted 1 m16 3 glocks on 2 nightmare mode purification ritual )