And don't forget the Remington Nylon 66 series of .22 Rim Fire Rifles. The stock which also held the metal parts of the action was made from Nylon. The rifle was virtually immune to wear, rust, corrosion and other ailments common to all steel rifles.
I suppose Nylon as used in gears and other sewing machine parts is far superior to regular plastic. ~~ BUT ~~ how to tell the difference in a used machine? That is still my quandary.
Joe