I had hunting property about 5 1/2 hours away from my residence and built a gravity feeder out of a 55 gallon heavy plastic barrel. I cut a hole through the bottom and installed a toilet flange. I necked down heavy pvc pipe until I got down to the size I wanted for enough 'flow' but not too much. I think that was a 2" ID piece. To that I glued on a 'T' and ran two small 'arms' off the short ends. I put end caps on the short arms then cut small 'troughs' on the top side of each arm and drilled drain holes in the bottom of the arms. I made a funnel for the inside of the barrel out of some aluminum sheet and pop rivets--that would feed the corn down the pipe as it was eaten out of the troughs below. The whole rig went on a triangular support between three trees, and was secured there. A larger piece of aluminum sheet formed a 'roof' over the locable barrel top. This set up would hold enough shelled corn for about 5 or 6 weeks. There was so much brouse that I don't think the supplements and corn were all that attractive, but I did find trails to the feeder when I went to the property. I mounted the feeder next to my 'sanctuary' area and never hunted in that area, so the deer felt right at home.
Good luck, Arch