Update: After about 10 tries, Knuckledragger dropped a level 1 Twin Hornet for me. Aww yeah! Thanks buddy!
I am doing this as well. So far Im lv 11 and I have a lv 0 Hornet and a Lv 4 bonus package. I hit an unforeseen problem. It gets INCREDIBLY easy. Not only do you have legendary weapons you also out lv your enemies. I was lv 10 b4 I hit Captain Flint. I killed him in about 5 sec with the hornet and bonus package. I am now sitting in sanctuary a little bored.