How far in will/can a chicken stick it's head to get feed out? I do have another piece I can add... well, it is actually that female piece that the piece screws into to cap it off.
The 22.5 degree elbows are not that long.
If you get a street 22.5 elbow, you can just slip it in and turn it in whatever direction you want to experiment with it. I think Home Depot sells them.
It looks like this