Discover unmatched reliability with the ProMag Industries RUG04 Heavy-Duty Magazine, engineered for precision and performance. Crafted in the USA, this rugged magazine is built to last with a lifetime guarantee against manufacturer defects. Each magazine features precision-wound springs made from heat-treated wire, ensuring smooth loading and durability in the field. Heat-Treated Chrome Silicon Wire Spring Manufactured & Assembled in the U.S.A. Easy Loading Rugged Construction Choose ProMag for a magazine that exemplifies strength and reliability.