Enhanced Piston Bolt Spring for Primary Weapons Systems PWS AR15 Piston System AR-15
Replacement Bolt spring for use with PWS piston kits, uppers, and rifles. Corrosion and Heat Resistant Type 302 Stainless Steel, Squared and Ground Ends Premium Spring. Primary Weapon Systems MK1 bolt spring for .223/5.56/300BLK piston systems. U.S.A. made.