Guide to Farm Rare Drops
Step 1. Start a mission on “cm_dreams”
Open the game and press “Create a Server”
Select a low difficulty so you can kill enemies easily and put “Invasion” in the Enemy reinforcement frequency so enemies spawn constantly.
Step 2. Go to the Armory at the temple
After getting armor and weapons (I personally recomend getting heavy armor and the Sulfatum), go to the armory part of the temple, this is were we will be killing enemies.
Step 3. Kill the enemies
Kill all the enemies you face going to this part of the level and clean the area.
Once all the nearby enemies are dead face this wall for a second or two and more enemies will spawn.
Just repeat this until you get the drops you need.
The rarest drops will take a long time, take this in count, but the killing achievements are faster to get (at least this is my personal experience).