Picasso. Insert free, polished bore. Lots of different colors that won't chip, too. Hittman, the increased sensitivity gained with tungsten over lead is well worth the added expense, to me. I could list another half-dozen benefits, but feel is #1. Due to the density of tungsten.
"Things turn out best for those who make the best of the way things turn out" - Zachary Troy Schrah - a young man with vision far beyond his years.