Delrin and nylon would be right up that alley
both are easy to machine
on another note,
i have heard of folks melting down old plastic milk jugs and creating HDPE slugs for machining.
( i very much want to try this
)
no special tools are required.
the guy cut up the jugs into ribbons and placed them in a steel pipe crucible mold and a 225°F (109°C) oven
it will take a few cartons, small pieces are best.
let it soak in the oven until melted and remove after the plastic has formed a cylinder
let cool until the slug contracts (or devise a hinge in the mold) and remove the slug
after the shootin' match solidifies, you are ready to machine at will
to make a bearing,
you could devise a pipe inside a pipe form to create the center bore, to eliminate having to core the center out
or you could go the old fashioned method of buying sheet material and heat it up slightly until pliable enough to form over a pipe mandrel.
you may need to do a bit of math to get the correct cut on the sheet, but it is well within reach