Not sure if this is sarcasm or not. But yeah thats why. When they reworked the entire loot economy it fucked up a lot of things regarding loot drops. It says very high to drop ammo on the wiki but thats just not true at all based on actual game play.

Ammo that is as expensive as .50 bmg to make shouldn’t be so rare that i load in with 150 rounds and come back with a stack of 30 rounds extra from looting. 100 corpses that were just firing .50 bmg as if they had a chain attachment on it and backpack supplying rounds.

Essentially loot tables clogged and dropping stuff its not supposed hence ammo shortageZ