I have found Delrin to be one of the toughest plastic materials anywhere and it is inexpensive. I make Delrin washers and spacers in the construction of motorcycles.
Are there any firearms parts manufacturers using Delrin to make grips, stocks, or any other rifle components. If not, I am curious the type of polymer and plastic compounds that are used for these parts.
Delrin is also a great material to machine as it does not gum up. Great stuff to work with.