This achievement is "missable"
and the quests starts in Markovna by Dragan. In Gallowsbog in the red marked area on my map below are ten rusty bombs.
Five of them have a green fuse and five bombs have a red fuse. The bombs with the red fuses are the right bombs. Don't touch the bombs with the green fuse
, otherwise the achievement is gone for this playthrough and you have to start a new playthrough or create a new hunter and play again to the quest.
After you have collect the five red fused bombs, go back to Dragan in Markovna and earn your achievement.