Dave Ultra High Molecular Weight PE would also be a good choice, Your a toolmaker I would like to hear your suggestions on machining.
I was thinking having a form toll made for the outside profile and ball end mill made to the inside profile to be mounted in the tail stock of a lathe.

Craig, I agree with UHMW as it wears very well and has a very low coefficient of friction. This part looks to be a prime candidate for injection molding.

Well I have received my two sample parts from my supplier. These parts are Urethane molded. Thanks to PGCA member Craig Budgeon who put me in touch with a model shop that specializes in small quantity precision casting of Urethane. I tried the wad finger on a small sample and was very pleased with the performance. I sent the two sample parts to Ken Burns and Tom Armbrust to evaluate and test for performance and longevity. So fingers crossed I beleive we are very close to the problem with avalibilty of wad fingers for 8 gauge MEC loaders. I will keep everyone posted as we move along.