Huckleberry was the same, leash biting, leg biting, "NO" didn't phase him, he was going to be the boss or he was going to die trying. I tried all the bitter sprays, none worked, he started licking them like a treat. Everything I tried just got him worked up, when he was little I could win these battles, I could be the boss because I could physically stop him from doing things, this began to change as he grew. Fighting is NOT the way to go with these guys, they are really good at harassing large animals to death, or near death, and if they get a thing in their head you cannot get it out by a show of force. Cant fight fire with fire, nobody wins that way.
Some folks hate them, but I got a shock collar. I set it on VERY tiny shock (level 2 out of 8, not at all painful, I tried it on myself), and let him have it when he picked a fight with the leash, only had to shock him twice and he as hasn't bite the leash in 4 months. Next I showed him the consquences of attacking my legs. Again it was a two shock lesson on a very easy setting that worked instantly and I have never had trouble since. The collar I got has the option of a tone, or a shock. Before I zapped him I said 'no' then beeped the collar, then zapped him. Before I did this 'no' didn't have a meaning to him, he didn't care what I said, this has changed. Now he responds to 'no' and to the tone from the collar, the beep is as effective as the shock. I haven't shocked him in probably 3 months, even when he was chasing a deer, the beep stopped him. He isn't scared of it, but he knows that it means the same thing as 'no'.
I know there is a hot debate over the use of shock collars, and I agree that rotten people can do rotten things with them, but one effective correction is easier on the dog than many, many smaller corrections. And it allows me to let him have greater freedom, we go off leash all the time, and I am confident that he will respond to verbal commands, and if he is out of voice range (never happened) I know that a beep will get him back to my side fast. So he gets to run more, get yelled at less, learn faster, and I have a dog that went from a handful to a pleasure (mostly) in about a week.