I concur with others in that Barnes with their X bullets have been making them and have most experience. From what I understand, they and now some other manufacturers have the technology to make the "pettles" open up that takes the place of the mushroom shaped expansion of many traditional jacketed lead core bullets.
http://www.barnesbullets.com/products/rifle/mrx-bullet/

Barnes has some alloy mixture in this MRX their newest version of the X bullets.

The only thing that I've read that in the early designs of solid copper or similar non-lead alloy bullets is that because the metal was less pliable than lead, they tended to cause more copper fouling in the rifling of the barrel. As I understand it, this has been minimized by the groove beltsthey now have in the bullet. So that less of the surface of the sides of the bullet press into the rifling leaving less copper fouling.