To stop a bird from flinging feed a half inch lip is needed, projecting out into the feed bin, assuming the feeder is designed intelligently and the feed naturally stays about 1.5" below the lip. And as others have said, do not mix feeds and encourage a bird to dig for the goodies.
Hanging a feeder won't do anything if it doesn't have a feed lip. You can go for one of the buckets and pvc elbow contraptions, they generally will help with feed waste, after all you have the birds eating with their head stuck in a bucket and down a pipe. They won't like it, roosters with big combs will like it even less. But it will help with feed waste.
What it won't do is stop rodents and wild birds from stealing the feed. If you don't have rodents yet, you will, just a matter of time when you leave the feed out unprotected.
Then you can hand feed. Congratulations, your parents would be proud to know you have become a chicken slave, tied to the coop twice a day. Even then your won't get as many eggs, grow as much meat, or have happy chickens. A hen's limit on egg laying is almost always protein, the are browsers, eating a little all day, not filling up like a predator and doing fine on one big meal a day. You restrict the feed, you restrict the eggs and weight gain on the broilers. The hand feeding will attract rodents and wild birds as well unless you give less than will fill up the chickens. Fine for pets, not so good for producing eggs or putting weight on broilers.
The solution is a proper treadle feeder with a proper feed lip, a feeder lip extension if you are one of those 1% of flock owners that develops a hen from hell that will rake feed out of even the best of feeders. A narrow and distant treadle also helps prevent feed raking, it stretches Ma Feathers out out bit, make her stretch for the feed, it also prevents the treadle from being overwhelmed by a flock of birds or rats or tree rats. Can't eat what they can't reach and taking turns doesn't last for long in the real world.
