Here is the full list of all 19 Barrel Boot Camp achievements.
Complete Rooftop course C.
Complete Rooftop course B.
Complete Rooftop course A.
Complete Roadway course C.
Complete Roadway course B.
Complete Roadway course A.
Find a secret location in Warehouse.
Complete Warehouse course C.
Complete Warehouse course B.
Complete Warehouse course A.
Complete Industrial course C.
Complete any course without missing a single shot.
Complete Industrial course B.
Complete Industrial course A.
Complete the same course 10 times consecutively.
Complete 20 consecutive attempts of any combination of courses on a single stage.
Find a secret location in Industrial.
Find a secret location in Roadway.
Find a secret location in Rooftop.