I couldn’t find a write-up on the damage thresholds online. So, here they are up to the Guard for all your damage vs ammo dilemmas and general convenience! All are hazard 5 scaling:
Swarmer: 15
Exploder: 24
Web Spitter: 47.88
Grunt: 108
Acid Spitter: 144
Slasher: 177.6
Septic Spreader: 324
Guard: 324
Happy hunting, and rock and stone!
Until they die, yep! I just took it from the official wiki. I didn’t include weak point or armor break numbers, so this is just the raw HP for normal body shots.