You aint kidding
As for farming the endbosses, try your luck with the Warrior but it aint gonna be pretty. His drop rate turns TO shyt when you kill him after the story mission is complete (where you call in the moonshot).
Everyone else wasn't bad in my experience. Picked up a Sham, Bee, Maggie, Sledges Shotgun, Hornet, Bonus Package, Veruc, and White Death fairly easily. Thinking about it now, I've killed The Warrior as many times as it took to collect those items combined and he hasnt dropped shyt.
Man fukk that nikka