Lapua Unprimed Brass Cases 308 Winchester (100pk)Lapua World class brass begins with high quality raw materials and superior smelting and metallurgical competence. Throughout the production process, the focus on quality control is consistent with Lapua's exacting standards. Particular attention is paid to hardness, solidity and grain structure. All Lapua brass is tested to 30% overpressure according to Commission Internationale Permanente, the agency that oversees ammunition and component producers