I wonder if sabot rounds could be used to reduce friction and eliminate metal fouling?
About 10 years ago I was given an old box of Remington Accelerator 30-06 plastic sabots by a friend of the family who had purchased them years earlier but never tried any out. All 20 rounds looked shiny and new.
I was disappointed with the accuracy and concluded that there was too much accuracy impeding variability associated with plastic sabots which is why they have never really caught on as a center fire rifle cartridge.