The basic essence of what you have there is the equivalent of a very active 2 to 3 year old child, who needs a lot of structure, activity, and attention... On top of that all puppies are in and of themselves high energy…, and you have one who was bred to run and hunt for long periods of time, so from his point of view, he's doing exactly what he's supposed to be doing.
 
He needs a job, so if you haven’t already, start practicing basic command training with him throughout the day to give him something besides the ball to occupy his mind.
But the only thing that is really going to help is to tire him out. He needs to run, so if you don't run, try running him along side a bike or get him trained onto a treadmill if you have one. Try to find a way to incorporate him into whatever it is you do for exercise so that you can both benefit from the experience. Weimaraner’s love to swim, so if you have a pool, swimming is a great way to use burn up lot of energy quickly to tire him out. You could have him retrieve the ball from the pool to double the benefits of your ball throwing times. 
Hide and seek is another hunting skill you can practice with the ball in the house.  Start out pretty easy until he learns the concept of the game, and then hide it in progressively harder places so it takes him more time and mental effort to find it.
 
He needs to learn that at different times of the day, there are different activities to be done; otherwise he’ll view all day as possible ball time. Once a ball session is over, don’t allow him to walk around with a ball in his mouth obsessing over it.  Ideally, you need to help him learn to ignore the ball when not in use, but if need be, just put all the balls out of reach until you initiate the next round of play.  When you put the balls away, give him something else enticing to focus on for awhile to take his mind off the balls. Try giving him a rawhide bone or stuffed Kong toy, or another one of those treat dispensing toys that are on the market (not a round one!).  Find different things (toys, chews, frozen block of ice…) that he’s allowed to have at different times throughout the day to keep him occupied, once it no longer holds his attention, don’t leave it lying around.  You need to put it away so that the next time you bring it out it’s special again.
 
There is no quick fix for a big active puppy… you’ve got another year or more before he hell start settling down a bit and doing more to manage his own time, until then you have to find ways to keep his mind and body active to guard against obsessive, destructive behaviors.

 I am sorry to say but that is what the dog was bred for. They are used in duck hunting . Maybe you should start teaching him how to dive for a decoy like the purina diving contest for dogs. You may have a natural on your hands.          ... k9athletes.wordpress.com/2008/04/04/dockdogs-2008-world-champion-...