I cast my own lead bullets, and I see very little leading.
On the other hand, I've loaded several thousand Berry's plated bullets, and they are darn good. Berry's states their bullets can be used to the midpoint of jacketed data, and the Thick Plate versions can go higher than that - my latest box of 9mm 115gr Hollow Base Round Nose Thick Plate states a max velocity of 1500FPS.
Also, the core of a jacketed bullet, being supported by the jacket, tends to be dead soft lead, while plated bullets are harder cast lead, as the copper plating doesn't lend much support to the bullet. I currently load Berry's plated in both 9mm and 7.62x39mm. Good stuff, Maynard.