Rise of the Tomb Raider · Survivor skill
Crafting Mastery
Crafting Mastery enables large-capacity ammunition and resource pouches to be crafted at Base Camps and increases ammunition crafted on the run.
How it works
The guide places Crafting Mastery in Survivor tier II, gated by mastering eight more skills in any category. It lists two effects: large-capacity ammo and resource pouches become craftable at base camps, and the amount of ammunition crafted on the run increases. WikiRaider separately says equipment can be crafted at any Base Camp when the needed skill is learned.
Read the supporting references
Check the edition and source version for patch-specific details. Guide methodology.