You can get an engineering book that is a standard reference used for selecting materials.
Materials and Design, Third Edition: The Art and Science of Material Selection in Product Design 
by Michael F Ashby

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You can eventually look at all the parameters such as corrosion resistance, density (for good ballistics), etc etc etc and you will always wind up with COST as one of the parameters. 

Bullets are expendables. They get discarded in use so they need to be cheap.
If you want to improved the self lubricating properties perhaps you can mix both powdered teflon and HBN in a powder coat resin and spray it on the bullets.
Or you could mix it in the normal lube and pan lube or use a RCBS or Lyman luber.