Well, propably you missed a shell type, because its an easy achievement! Or I read some other forums, and the problem is: when you made a bomb, you didn't left the crafting table, that maybe help.
And a Make one of each bomb, you have 10 effect types 4 shell types and 3 gunpowder types! Thats a lot of bomb types! Try to watch some videos on youtube, try to view other forums, google it etc. You are going to do this achievement I've got the feeling!