300 Whisper Brass SSK stocks new factory Hornady brass and dies correctly made and dimensioned. Call 740-264-0176 for current prices and availability of primed and/or unprimed cases as well as factory ammo by Hornady and Cor Bon. Beware of cases made from 223 brass. Neck wall thickness varies a great deal as does the thickness of the taper from case mouth to end of the neck. Case capacity varies a lot. It is possible with brass made for 223 to encounter a situation where the round does not chamber fully and cannot be ejected by conventional means. “T” handles have been broken attempting to eject such a case. NEVER attempt to eject a loaded round by using a cleaning rod or anything else by inserting it into the bore and attempting to drive the round out. Prior to new factory brass SSK marketed brass remanufactured from from 223 cases with the case necks swaged to correct dimensions.