High-tensile strength, precision-made, carbon steel springs from Wolff help you achieve reliable cycling and top performance from both hunting and competition shotguns. Replace weakened springs for better performance or use as part of a custom project for ultimate reliability.Wolff’s exceptional quality, extra power shotgun magazine tube springs ready to drop-in to the models listed below – no gunsmithing required. Rem 870 is 10% extra power and fits 3- to 5-round 12 gauge magazine tubes. SPECS: High-tensile, heat-treated spring steel. Gunsmith fitting required for some springs as indicated.