Because the plastic tip would replace most the lead innards in the nose of the Partition, and the purpose of the plastic tip is to * give a better aerodynamic shape for longer shots * give better weight distribution for flight stability for longer shots * no deform in the magazine under recoil * upset the lead beneath it to initiate rapid expansion at lower impact velocities on game at long ranges
But Winchester and Barnes are working on something like that with their new polymer tipped bullets.
And I picked up Winchester Supreme Ballistic Silvertip and Accubond ammo at Wal-Mart for $9.00 a box yesterday.
