According to Mr John Henwood ( The Forgotten Winchesters, pub:1995), 158 gr reduced .358"d bullets work fine. He recommends reducing it in stages using two reducing dies. "Spring back" of the copper jacket refers to the fact that when you cold compress un annealed metals, all attempt, to some extent, to return to their larger size. The reduction process squeezes the bullet, it doesn't trim them. Bullet jacket metal does this to a much greater extent than lead. By 'greater extent', I mean that if you reduce a .358" jacketed bullet, to .3508", the jacket can spring back to about .351". There could very well be a void between the lead core and jacket by as much as .0001. Not much, for sure, but a separation never the less. I doubt that the jacket will actually separate from the core at the velocities the .351 operates. Too, such a reduction will force some of the core material (lead) out of the jacket. The nose could even become distorted. Professionals who do this reduction usually have a point-up die to reshape the reduced bullet's nose, but the only way to cure spring back is to reduce the bullet a few thousand's more than the final diameter, and then reswage the bullet to final diameter. For jacketed calibers above 30 caliber, this reswage is best done using a high pressure swaging press. An alternative is to cast your own .351 bullets if you can find a mold. While the .351wsl is an OK whitetail gun in dense woods/heavy brush, you'll be spending hours trying to find those expensive brass in the grass. Therefore, cast bullets on the range, where your brass is easily picked up is just as much fun as using jacketed bullets.
