I'll echo what GB said. If using 30-30 brass I necksize after fireforming,If I am using Federal 7-30 brass then I full length size the first time and neck size after that. Never had a problem. Hornady makes a 7mm short neck sizing die that is not cartridge specific,but caliber. Therefore,it works for several different cartridges,just adjust the height. Got mine from Graf and Sons.. :grin: