You're wasting your money dumping corn in the summer time. For $15-20 you can do 4-5 mineral sites that will only need refreshed once a month. Stick a camera on each one and you'll get pics. They stop hitting the minerals come deer season though.
The biggest reason to run corn in the summer is to establish the bait site for hunting season. I have noticed that bigger bucks tend to accept a corn pile better if it existed for a while before they peeled velvet. They get accustomed to it in the summer and have no reason to doubt its safety later.