You know, I thought workstations all had a 20% chance to find their schem. I swear that's what was in the patch notes... but in reality, that's not the case.
They actually scale so that the higher Int-required ones have an ever smaller chance to drop.
25% for Forge, 12.5% for Workbench and Mixer, then all the way down to 4% for Chem Stations
<!-- cntCollapsedForge -->
<lootcontainer id="91" count="1" size="7,4" sound_open="forge_open" sound_close="forge_close" loot_quality_template="qualBaseTemplate">
<item group="forgeLoot"/>
<item name="forgeSchematic" prob=".25"/>
</lootcontainer>
<!-- cntCollapsedWorkbench -->
<lootcontainer id="92" count="1" size="7,4" sound_open="open_workbench" sound_close="close_workbench" loot_quality_template="qualBaseTemplate">
<item group="workbenchLoot"/>
<item group="groupToolsTiered" prob=".2"/>
<item group="groupRareToolsTiered"/>
<item group="vehiclePartsTiered" prob=".2"/>
<item name="workbenchSchematic" prob=".125"/>
</lootcontainer>
<!-- cntCollapsedCementMixer -->
<lootcontainer id="93" count="1" size="7,4" sound_open="cement_mixer_open" sound_close="cement_mixer_close" loot_quality_template="qualBaseTemplate">
<item group="cementMixerLoot" count="1" />
<item name="cementMixerSchematic" prob="0.125"/>
</lootcontainer>
<!-- cntCollapsedChemistryStation -->
<lootcontainer id="94" count="1" size="7,4" sound_open="chem_station_open" sound_close="chem_station_close" loot_quality_template="qualBaseTemplate">
<item group="labEquipment" prob="0.48"/>
<item group="chemistryStationLoot" prob="0.48"/>
<item name="chemistryStationSchematic" prob="0.04"/>
</lootcontainer>
Back on subject,
Silencers only drop from ModGunT2 loot group, which only appears near the bottom of the groupModAllT2 loot group, which in turn comes from groupQuestMods and groupModAllScaled. Now groupModAllScaled comes from a number of places, but each one is only a tiny chance of being the silencer, rolling against all other mods.
groupBuriedWeaponChest
groupHeroChestLootSub
groupSafeLoot
groupAmmoPileLootSub
groupWeaponsBagLoot
groupBuriedLootStashTreasureSub
<lootcontainer id="40"> <!-- military munitions ammo box -->
<lootcontainer id="50"> <!-- shotgun Messiah -->
<lootcontainer id="71"> <!-- EntityLootContainerStrong, rare random drop off strong zombies -->
<lootcontainer id="73"> <!-- EntityLootContainerBoss, rare random drop off bosses -->
<lootcontainer id="95"> <!-- cntLootCrateHero, Hero / Hidden Stash Cardboard Loot-->