I agree, there should never be a significant load that would push the ball out. Spherical rod end bearings are meant for radial loads. Just FYI, here is some data from the Aurora catalog (lbs):
Model Number Use Hole Size Shank Thread Ultimate Static Radial Load Proof Axial Load
SPM-8 Low-cost commercial 0.500" 1/2-20 6430 10% max 3-pc
15% max 2-pc
MM-8T Gen Purp, Teflon liner " " 6660 "
ASM-8T Aerospace $$$ " " 19500 2040
Depending on the bearing you select, its strength can vary over a wide range but loading any type axially is a bad idea.
Regards, Neil Tucson, AZ