Trina I only had this problem when my chicks were little. Now that they are more adult size they peck with such vigor that I never have to manually knock the feed loose. :)
Mine are tall too, at 5 ft tall, (I am 5'3") and I could never pick up that big bag to fill them so I use a homemade scoop made from a half gallon milk bottle. I just cut off the bottom. It holds quite a bit and pours from one corner without spilling.
Matt, I found the bottom of the bottle to be a little too thin and therefore didn't have enough bite to hold the nipple in with chicks pecking at it. So I flipped the bottle upside down and put the nipple in the cap. It is thicker so more area of contact with the threads on the nipple. I also...