good evening;
Failed experiment fire forming new PPU 300 Winchester magnum brass.
Wanted extra .375 h&h brass. Dimensions looked close so got 50 new 300 Win mag cases. Used tapered expanders to open mouth of 25 cases. Last resizing to 375h&h was done with a Lee sizing die. Cases looked great.
Fired in 375h&h model 70 Winchester rifle, case body looked great, the shoulder of case sort-a ok, actual neck of case less than 1/16 of inch. No neck wonders. Bought that lesson. Gave remaining unresized brass to friend.
rp