that one guy saying poison ammo still oneshots hives and armoreds hasn't played the game for a year or lied. hives take like 6 shots to kill with poison compact, armoreds take 2, hellhounds do get oneshotted, but hives and armoreds make up the bulk of your xp in PVE if you do XP runs.
poison ammo is so fucking useless for no reason, it was supposed to be better for PVE than incen due to quieter kills but its a massive waste of ammo.