My father in law gave me a .35 Brown-Whelen in a 1917 Enfield action. It's a .35 Whelen AI with the shoulder pushed forward, neat looking round. I asked about fireforming, and he told me he just shot .30-06 in the chamber and fireformed them. I asked him haw many firings he got before head separation, and he just looked at me funny. I later started necking brass up to .375, necking back to .35, and jamming a .35 bullet into the lands in fireforming loads. Worked well with no case loss, and no headspace issues. For giggles, I did it his way once. It worked, but I'm not sure where that bullet went.
