Kill 3 targets or more using an explosive object in any level.( 10G)

To unlock this achievement, you need to kill at least 3 enemies by shooting an explosive barrel, that can be found during numerous missions. They are almost always red and are either barrels, or gas canisters. A good mission to attempt this is 'Narco Hell' as you are making your way through the drug labs. There are a lot of explosive barrels lying around, so try to allow enemies to congregate around one of them and blow it up.