Copper cap billets have been the go too for knappers for decades. The 1 3/8" Copper cap billet is perfect size for the initial reduction of medium to large spalls. These lead filled billets give unmatched performance and accuracy when its needed the most. While this line of billets provide great performance they do wear over time. If you're looking for a billet line that is designed for heavy use check out our Solid Head Copper Billets.